Dometic NDA1402, NDE1402 Service Manual

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DIAGNOSTIC SERVICE MANUAL

NDA1402 & NDE1402

WITH AUTO DEFROST

USA Dometic, LLC. 2320 Industrial Parkway Elkhart, IN. 46516 574-294-2511

CANADA Dometic, LLC. 46 Zatonski Unit 3 Brantford, Ontario CANADA N3T 5L8 519-720-9578

foreword

This service manual is the result of the dedication of Dometic, LLC technical staff and its engineers in giving service people the necessary instruction for making accurate analyses of certain conditions. Provided is a diagnostic chart

leading a qualied mechanic into the service

manual pages to locate and solve symptoms which may occur. Dometic, LLC has continued its commitment in providing service people with this, the most up-to-date information about servicing Dometic RV accessories.

Safety InStructIonS

This manual has safety information and instructions to help users eliminate or reduce the risk of accidents and injuries.

recognIze Safety InformatIon

This is the safety-alert symbol. When you see this symbol in this manual, be alert to the potential for personal injury.

Follow recommended precautions and safe operating instructions.

underStand SIgnal WordS

A signal word, WarnIng OR cautIon is used with the safety-alert symbol. They give the level of risk for potential injury.

Indicates a potentially hazard-

ous situation which, if not avoided, could result in death or serious injury.

Indicates a potentially hazard-

ous situation which, if not avoided may result in minor or moderate injury.

When used without the safety

alert symbol indicates, a potentially hazardous situation which, if not avoided may result in property damage.

Read and follow all safety information and instructions.

contentS

Page no.

DIAGNOSTIC FLOW CHART..........................................................................6

SectIon 1

oVerVIeW/oPeratIon

Refrigerator Overview/Operation..........................................................................9

SectIon 2

ac Voltage

AC Voltage Requirements...................................................................................12

SectIon 3

ac comPonentS

3.1 Heating Element.........................................................................................12

3.2 Interface Module.........................................................................................13

3.3 AC Sensing.................................................................................................14

SectIon 4

dc Voltage

4.1 DC Voltage Requirements ....................................................................... ..14

4.2 Grounds......................................................................................................14

SectIon 5

dc comPonentS

5.1 Door Switches and lamps.........................................................................

5.2 Temperature Sensors................................................................................

5.3 Low Ambient Control.................................................................................

5.4 Frame Heater............................................................................................

5.5 Interior Fans..............................................................................................

5.6 Thermo Fuse..............................................................................................

5.7 Flame Sensing...........................................................................................

5.8 Ignition Control Module..............................................................................

5.9 Electrode....................................................................................................

5.10 High Voltage Cable....................................................................................

5.11 Solenoid (Gas)..........................................................................................

5.12 Front Display Panel...................................................................................

5.13 Lower Board.............................................................................................

5.14 Fuses........................................................................................................

14 15 15 15 16 16 16 17 17 17 18 18 21 21

SectIon 6

lP gaS

LP Gas Requirements.......................................................................................22

contentS

Page no.

SectIon 7

lP gaS comPonentS

7.1 Manual Gas Shutoff Valve........................................................................22

7.2 Orice.......................................................................................................22

7.3 Burner.......................................................................................................23

7.4 Flue Bafe................................................................................................23

7.5 Flue Cap..................................................................................................23

7.6 Flue Tube.................................................................................................23

SectIon 8

coolIng unIt

8.1 Cooling Unit......................................................... ....................................23

8.2 Ventilation.................................................................................................25

8.3 Ventilator Fans.........................................................................................27

8.4 Leveling....................................................................................................27

8.5 Food Storage...........................................................................................27

8.6 Ambient Temperature...............................................................................27

SectIon 9

froSt

9.1 Door Seals...............................................................................................27

9.2 Interior Liner Seal to Frame.....................................................................28

9.3 Drain Tube...............................................................................................29

9.4 Wall Entrances.........................................................................................29

9.5 Auxiliary Defrost Fan................................................................................29

9.6 High Humidity...........................................................................................29

9.7 Door Position...........................................................................................29

SectIon 10

defroStIng

10.1 Real Time Clock.....................................................................................30

10.2 Automatic Defrosting..............................................................................30

10.3 Manual Defrosting..................................................................................31

10.4 Drying Function......................................................................................31

10.5 Freezer Defrost Heating Element..........................................................31

10.6 Fresh Food Defrost Heating Element....................................................32

10.7 Drain Tube/Tray Defrost Heating Element.............................................32

contentS

Page no.

SectIon 11

trouBleSHootIng

11.1 Status Messages.....................................................................................33

11.2 Error Codes.............................................................................................34

11.3 Service Mode..........................................................................................36

SectIon 12

Ice maKer

12.1 Operation............................................. ..............................................38

12.2 Mold Heater...........................................................................................38

12.3 Ice Ejector..............................................................................................38

12.4 Mold Thermostat....................................................................................39

12.5 Shutoff Arm............................................................................................39

12.6 Mold Switches......................................................................................39

12.7 Timing Motor..........................................................................................39

12.8 Water Valve...........................................................................................39

12.9 Ice Maker Replacement........................................................................40

12.10 Water Fill Adjustment............................................................................40

12.11 Fill Tube................................................................................................40

12.12 Water Supply........................................................................................41

12.13 Wiring...................................................................................................42

SectIon 13

door dISPenSer

13.1 Operation................................................................................................46

13.2 Auger.......................................................................................................46

13.3 Solenoid.............................................................................................. .. . .. 47

13.4 Ice Shutter...............................................................................................47

13.5 Water Dispenser......................................................................................48

13.6 Door Mechanism and Display Panel........................................................48

SectIon 14

WIrIng

14.1 Internal Wiring........................................................................................48

14.2 External Wiring.......................................................................................48

14.3 Wiring Schematics..................................................................................48

SectIon 15

mIScellaneouS

15.1 Thermistors............................................................................................49

This service manual will address the most common system problems associated with the NDA 1402 and NDE 1402 refrigerators supplied by Dometic, LLC. Our intent is to provide you with a guideline of checks to make, should you encounter one of the following symptoms.

SYMPTOM

1. No operation - no panel lights

2. No operation - has panel lights

3. No AC operation - operates on gas mode

CAUSE

Operation DC Volts Fuses Wiring Front Display Panel Lower Circuit Board

Operation DC Volts Temperature Sensors Wiring Lower Circuit Board

Operation AC Volts Fuses Heating Elements Wiring Lower Circuit Board

SECTION & PAGE

1, page 09 4, page 14 5, page 21 14, page 48 5, page 18 5, page 21

1, page 09 4, page 14 5, page 15 14, page 48 5, page 21

1, page 09 2, page 12 5, page 21 3, page 12 14, page 48 5, page 21

4. No Gas operation - operates on AC

mode

5. Insufcient cooling on all modes.

6. Insufcient cooling on AC - cools prop-

erly on gas mode.

Operation LP Gas Manual Gas Valve Ignition Control Module High Voltage Cable Electrode Solenoid (Gas) Wiring Lower Circuit Board

Ventilation Ventilator Fans Leveling Ambient Temperature Drain Tube Wall Entrances Temperature Sensors Cooling Unit

AC Volts Heating Elements Lower Circuit Board

1, page 09 6, page 22 7, page 22 5, page 17 5, page 17 5, page 17 5, page 18 14, page 48 5, page 21

8, page 25 8, page 27 8, page 27 8, page 27 9, page 29 9, page 29 5, page 15 8, page 23

2, page 12 3, page 12 5, page 21

SYMPTOM

7. Insufcient cooling on Gas - cools

properly on AC mode.

8. Water on frame

9. Rapid formation of frost

CAUSE

LP Gas

Orice Flue Bafe

Flue Tube Burner Lower Circuit Board

Interior Liner Seal to Frame Wall Entrances High Humidity Frame Heater

Food Storage Interior Liner Seal to Frame High Humidity Door Seals Drain Tube Wall Entrances Auxiliary Defrost Fan

SECTION & PAGE

6, page 22 7, page 22 7, page 23 7, page 23 7, page 23 5, page 21

9, page 28 9, page 29 9, page 29 5, page 15

8, page 27 9, page 28 9, page 29 9, page 27 9, page 29 9, page 29 9, page 29

10. Unit is not defrosting

11. Frost around drain tube

12. General Frost (freezer)

13. General Frost (fresh food)

Real Time Clock DC Volts Temperature Sensors Freezer Defrost Heating Element Drain Tube/Tray Heating Element Fresh Food Heating Element

Drain Tube orice is too Small

Drain Tube/Tray Heating Element Wall Entrances

Door Seals Interior Liner Seal to Frame Wall Entrances Drain Hose Freezer Defrost Heating Element Drain Tube/Tray Heating Element

Door Seals Interior Liner Seal to Frame Wall Entrances Drain Hose Fresh Food Heating Element Drain Tube/Tray Heating Element

10, page 30 4, page 14 5, page 15 10, page 31 10, page 32 10, page 32

9, page 29 10, page 32 9, page 29

9, page 27 9, page 28 9, page 29 9, page 29 10, page 31 10, page 32

9, page 27 9, page 28 9, page 29 9, page 29 10, page 32 10, page 32

SYMPTOM

14. Ice maker fails to start

15. Not making enough ice

16. Ejector blades frozen into ice

17. Ice around ice maker

18. No ice or water at the dispenser

CAUSE

Operation Mold Thermostat Shutoff Arm Water Valve Interface Module

Operation Mold thermostat

Water Fill Adjustment Water Supply Water Valve

Water Fill Adjustment Water Supply Fill Tube

Operation Lock Out Feature Freezer Door is Open Door Mechanism and Display

Panel

Interface Module

SECTION & PAGE

12, page 38 12, page 39 12, page 39 12, page 39 3, page 13

12, page 38 12, page 39

12, page 40 12, page 41 12, page 39

12, page 40 12, page 41 12, page 40

13, page 46 13, page 46 13, page 46 13, page 48

3, page 13

19. No ice at the dispenser

20. No “cubed” ice at the dispenser

21. Water/Condensation at the dispenser

Operation Lock Out Feature Freezer Door is Open Door Mechanism and Display

Panel Auger Interface Module

Operation Door Mechanism and Display

Panel Solenoid Interface Module

Water Fill Adjustment Ice Shutter High Humidity

13, page 46 13, page 46 13, page 46 13, page 48

13, page 46 3, page 13

13, page 46 13, page 48

13, page 47 3, page 13

12, page 40 13, page 47 9, page 29

SectIon 1

uSIng tHe control featureS

refrIgerator oVerVIeW

aBSorPtIon coolIng SyStem

In an absorption refrigerator system, ammonia is liqueed

in the nned condenser coil at the top rear of the refrig-

erator. The liquid ammonia then ows into the evaporator

(inside the freezer section) and is exposed to a circulat-

ing ow of hydrogen gas, which causes the ammonia to

evaporate, creating a cold condition in the freezer. When

starting this refrigerator for the very rst time, the cooling

cycle may require up to four hours of running time before the cooling unit is fully operational. The tubing in the

evaporator section is specically sloped to provide a con-

tinuous movement of liquid ammonia, owing downward

by gravity through this section.

ImPortance of leVelIng

Leveling is one of the requirements for proper operation with absorption refrigerators. To ensure proper leveling the vehicle needs to be leveled so it is comfortable to live

in (no noticeable sloping of oor or walls). Any time the

vehicle is parked for several hours with the refrigerator operating, the vehicle should be leveled to prevent this loss of cooling. If the refrigerator is operated when it is not level and the vehicle is not moving, liquid ammonia will accumulate in sections of the evaporator tubing. This will slow the circulation of hydrogen and ammonia gas, or in severe cases, completely block it, resulting in a loss of cooling. When the vehicle is moving, the leveling is not critical, as the rolling and pitching movement of the vehicle will pass to either side of level, keeping the liquid ammonia from accumulating in the evaporator tubing.

automatIc defroStIng control SyStem

This refrigerator is equipped with an automatic defrosting control system. The defrost system will automatically carry out a defrost of the frozen food and fresh food compartments once every 24 hours. To be able to control the performance of the defrost intervals the system is equipped with a built in real time clock. The clock has to be set to local time at the very rst start up of the refrigerator or when the 12 volt DC supply has been disconnected for a long period of time. A message on the LED display panel will alert when the clock needs to be set. It is also recommended to reset the clock when entering different time zones.

modeS of coolIng

nda1402: This refrigerator is equipped with an automatic

energy selector system which automatically selects the most suitable energy source that is available, either 120 volt AC or LP gas operation. The system can be set by the user to be fully automatic, or to operate on LP gas only.

nea1402: All-electric operation.

NEA1402

1. ON/OFF button. Press this button to turn the refrigerator on and off.

2. STORE button. (NEA1402) AUTO/STORE button. (NDA1402) Combined energy mode selection and store button.

3. LED display panel.

4. SET button. Combined temperature range and real time clock ad- justment.

NDA1402

led dISPlay Panel

The LED panel displays temperatures in the refrigerator, current modes of operation and other useful status messages.

The displayed temperature values reect the most probable temperature of the food in the two compartments. A delay function prevents rapid changes due to door openings etc.

Panel Indications:

•

The most probable temperature of food in the frozen food compartment. The most probable temperature of food in the • fresh food compartment. AUTO mode indication (NDA1402)• AC operation indication.• GAS operation indication (NDA1402)• Thermostat setting indication (temporary during • setting). Real time clock/ PM indication (temporary during • setting). Various status and error messages.•

Store functIon

When setting the real time clock as well as the thermostat, the desired setting is stored automatically after 5 sec. of inactivity or by pressing the STORE button.

oPeratIon

Before starting the refrigerator, check that all the manual gas valves are in the “ON” position. DO NOT forget the manual shutoff valve on the rear of the refrigerator. The NDA1402 model refrigerator is equipped with a control system which can be set to automatically select either 120 volt AC or LP gas operation (AUTO mode), or if desired LP gas only (GAS mode). The NDE1402 model refrigerator is an all electric 120 volt AC operation.

most lP gas appliances used in recreational vehicles are vented to the outside of the vehicle. When parked close to a gasoline pump or traveling through tunnels, it is possible that the gasoline fumes could enter this type

of appliance and ignite from the burner ame,

cauSIng a fIre or an eXPloSIon.

for your Safety, when refueling or traveling through tunnels, shut off all lP gas appliances which are vented to the outside.

deScrIPtIon of oPeratIng modeS auto mode

When operating in the AUTO mode, the AUTO mode indicator dot is lit. The control system will automatically select between AC and GAS operation with AC having priority over GAS. (An indicator dot will be lit to inform of the energy source selected). If the control system is operating with AC energy and it then becomes unavailable, the system will automatically switch to GAS. As soon as AC becomes available again the control will switch back to AC operation.

gas operation (120 volts AC is not available). The control system will activate the ignition system and will make three attempts to light the burner for a period of approximately 45 seconds with two minutes rest (purge) interval. If unsuccessful, “ch LP” will be displayed. To restart an ignition attempt with “ch LP” in the display turn the unit off, wait a few seconds and turn back on. The control system will attempt a new ignition sequence. If 120 volts AC becomes available while “ch LP” is displayed, the refrigerator will operate on AC but the “ch LP” will not turn off until the main power ON/OFF button is pressed to the “OFF” then “ON” position.

automatIc energy Selector control SyStem

The NDA1402 model is equipped with an automatic energy selector control system. The user turns the refrigerator on and selects the desired temperature and then, the control system selects the most suitable energy source available (either 120 volt AC or LP gas operation). The system can be set by the user to be fully automatic (AUTO mode ON) or to operate on LP gas only (AUTO mode OFF).

The NDE1402 model is an all electric operation.

Press AUTO/STORE button to select AUTO mode operation or to chose LP-gas mode of operation only.

modeS of oPeratIon (auto) & (gaS)

When the refrigerator is in the AUTO mode, it automati-

cally uses the most efcient energy source that is avail-

able for operation. Should a more efcient energy source

become available during operation, the refrigerator will change from the current energy source to the more ef-

cient energy source as follows:

gaS mode

When operating in the GAS mode, the AUTO indication dot will be off and the GAS indication dot is lit. This mode provides LP gas operation only. The control system will activate the ignition system and will make three attempts to light the burner for a period of approximately 45 seconds with two minutes rest (purge) interval after each trial. If unsuccessful, “ch LP” will be displayed. To restart GAS Operation, press the main power ON/OFF button to the “OFF” and then “ON” position. The control system will attempt a new ignition sequence. If the refrigerator has not been used for a long time or the LP tanks have just been

relled, air may be trapped in the supply lines. To purge

the air from the lines may require resetting the main power ON/OFF button three or four times. If repeated attempts fail to start the LP gas operation, check to make sure that the LP gas supply tanks are not empty and all manual shutoff valves in the lines are turned on.

to Shut off the refrigerator

The refrigerator may be shut off while in any mode of operation by pressing the main power ON/OFF button to the “OFF” position. This shuts off all DC power to the control system including the interior light.

•

AC operation (if 120 volt AC is available). AC operation is only possible in AUTO mode. GAS operation (if 120 volt AC is not available).•

GAS mode (manual LP gas operation)

When the AUTO mode is turned off, the refrigerator uses gas as an energy source - even if AC is available.

1110

Start uP

tHermoStat SettIng

NDE1402:

Turn on the refrigerator by pressing the ON/OFF button.

NDA1402:

fIre Hazard. If the refrigerator has not been used for some time, and before lighting the gas burner. check that the gas path between the burner jet and the burner tube has not been obstructed. failure to heed

this warning could cause a re resulting in

death, severe personal injury and property damage.

•

Before turning on the refrigerator, verify that all the manual gas valves, including the manual shut off valve, are in the “ON” position.

•

Turn on the refrigerator by pressing the ON/OFF button.

The freezer and the fresh food compartment temperatures are controlled separately and independently of each other, based on the actual air temperature in each compartment.

•

The freezer setting is pre-set (can not be changed) to be approx. 0°F (-18°C) when running on AC. If running on GAS the pre-set temperature is approx. 7°F (-14°C).

•

The fresh food compartment can be set in 5 different positions (1-5) where 5 is the coldest setting which gives a fresh food temperature of approx. 33°F (0°C). Setting 3 gives a temperature of approx. 37°F (3°C).

NEA1402

NDA1402

real tIme clocK

NEA1402

PM INDICATION

If the real time clock has to be set, the LED panel will

show ashing horizontal bars ” -- -- “.

To enter “TIME MODE”, keep the SET button pressed

• until gures ash on the LED panel.

(Hours are to the left and minutes to the right.)• Press the SET button to adjust to local time. AM/PM • should also be set here. Store each setting by pressing the AUTO button (NEA •

1402) - AUTO/STORE button (NDA 1402) or use the automatic store function (wait 5 sec.).

HOURS

MINUTES

NDA1402

MINUTES

note: It is important to check the clock setting every

month and to reset when entering different time zones. This is to allow proper defrosting daily at 1:00 am.

Press the SET button to set the thermostat. Thermo-• stat range is 1 to 5, where 5 represent’s the coldest compartment temperature.

Press the STORE button to store or use the automatic

•

store function (wait 5 sec.).

manual defroSt

NDE1402

NDA1402

The refrigerator can be set to defrost at any time. Usually a defrost cycle takes about 1 hour but will depend on the amount of frost and could therefore vary from time to time.

•

Switch off the refrigerator with the ON/OFF button. Press and hold the AUTO button (NEA 1402) - AUTO/ •

STORE button (NDA 1402). Then, press the ON/OFF button. “dE Fr” is displayed.

The drip tray catches small spills. The tray is removable and dishwasher safe.

It is not a drain; pour water directly into this area.

DO NOT

Ice dISPenSer (oPtIonal)

For a refrigerator to provide ice through the door, the ice

maker rst dumps the ice it produces into a large bin. To

request ice at the door, select Cube or Crush and then press the lever. This will activate a switch which turns on a motor that rotates the auger. When the auger rotates, it pushes ice out of the bin, through a chute right into the glass. To stop dispensing, pull the glass away from dispensing arm before the glass is full. Allow the ice chute to clear before removing the glass.

SectIon 2 ac Voltage

ac Voltage reQuIrementS

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

The refrigerator is a 120 volt AC, 60 Hz appliance. The proper operating range is 108 to 132 volts. If the voltage

drops below 108 volts, cooling efciency will decrease as

the voltages decreases. Check the AC volts at the receptacle where the refrigerator is attached. If the voltage is outside of the proper operating range, correct the power source problem.

120 Volt ac receptacles

Might have separate power cords if unit has an Ice Maker

Water dISPenSer (oPtIonal)

The water dispenser works much like the ice dispenser. To request water at the door, simply press the lever. This will activate a switch which turns on an electric water valve

at the back of the refrigerator. Water will ow through a

separate tube right into the glass.

note: The NDA/NDE1402 models use “Non-chilled”

water at the door dispenser.

locK out feature

The ice dispensing system can be locked out to prevent unwanted use.

lock out•

To lock out, press the “Lock” pad for (3-5) seconds until the RED light above the Padlock comes on.

unlock•

To unlock, press the “Lock” pad for (3-5) seconds until the RED light above the Padlock goes out.

dISPenSer lIgHt

The light can be turned on and off by pressing the “Light” touch pad. The light will illuminate the dispenser area. The light will also turn on automatically when ice or water is dispensed.

automatIc PoWer SuPPly SWItcH off

For safety reasons, when opening the freezer door, the ice/water dispenser and ice maker system will automatically shut off. Closing the freezer door automatically resumes operation of ice/water dispensing and ice maker operation.

The refrigerator is equipped with a three-prong (grounding) plug for your protection against shock hazards and should be plugged directly into a properly grounded three prong receptacle. ing prong from this plug! The free length of the cord is 3 feet. It is recommended that the receptacle is located to the right side of the refrigerator (viewed from the rear). The receptacle should be 3” (from the bottom of the

plastic receptacle) above the refrigerator mounting oor.

This allows easy access through the vent door. The cord should be routed to avoid direct contact with components that could damage the cord insulation. The refrigerator will not switch to another mode of operation until all AC power is lost.

do not cut or remove the ground-

SectIon 3 ac comPonentS

3.1 Heating element

The heating elements are designed to deliver a predetermined amount of heat to the cooling unit. To check a heating element, remove the heater leads from the printed circuit board and measure for proper resistance across the two leads with a properly calibrated Ohm meter. This check is to be done with the heating element at room temperature. You should obtain the following readings ± 10%.

1312

model Watts ohms amps

NDA 1402 420 34.3 3.5 NDE 1402 420 34.3 3.5

The NDA/NDE1402 models use two AC heaters wired in series. The resistance should be 34.3 Ohms +/- 10%.

note: never over or under size the ac heater.

3.2 Interface module

The interface module is used for two reasons:

The tabs on the module are from left to right:

•

(4) Interconnected tabs that serve as interconnection points of four neutral wires (white). (2) Interconnected tabs that serve as intercon-• nection points of the “auger wire” from the door and the wire to the auger motor (yellow). (2) Interconnected tabs that serve as intercon-• nection points for the “cube wire” from the door and the wire to the solenoid (red). (2) Interconnected tabs that supply switched 120

•

volt AC to the door and to the ice maker (black). (1) Tab for incoming 120 volt AC to the interface • module (black).

To shut off the 120 volt AC supply to the door dispens-

•

er and ice maker when the freezer door is opened (for safety Reasons).

To shut off the 120 volt AC supply to the door dispens-• er and ice maker when the refrigerator is switched “OFF” by means of the ON/OFF button on the upper display panel.

The function of this additional module is very simple. It has a (5 amp) fuse for incoming 120 volt AC line voltage and a relay that switches the line voltage ON/OFF. The relay is driven by a circuit that senses the voltage at the node between the door switch and the interior lamp. This relay is controlled by the wires in the P1 connector on the interface module. These wires are hooked on the wires coming from the power module to the lamp and door switch. The black wire is ground (-), the white wire is 12 volt DC (+) and the yellow wire is going to the connection point between the lamp and door switch. If the door is opened, the yellow wire should be 12 volt DC (+) and if the door is closed, the reading should be 0 volts DC. If the lamp is lit or if 12 volt DC is absent, the relay will drop out and 120 volt AC will not be supplied to the ice maker or the door dispenser.

To troubleshoot the module:

Check that the wires are correctly connected to

•

the tabs. When the door is shut, check that 120 volt AC is • present on the tabs (J9) and (J10). When the door is open, check that the voltage on • these tabs (J9) and (J10) is 0 volts AC. If 120 volts AC is not present on (J9) and (J10) • when door is closed, check the fuse. If the fuse is OK, check that the interior light in the • freezer is working, (switched on/off when pressing/releasing the door button). If the interior light is OK, check if the relay is • “clicking” when the door is opened/closed (you will need an assistant to operate the door while

you are touching the relay with a nger to sense

if it is “clicking”. If the relay is not clicking though the interior light • is correctly switched ON/OFF, measure the voltages on the pins in the P1 connector. The voltages should be as described previous, in this section. If the voltages in the P1 connector are OK and • still the relay is not clicking when opening/closing the door, the module is faulty; the transistor that drives the relay is probably damaged.

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

3.3 ac Sensing

The incoming 120 volt AC supply is constantly checked for availability by means of an opto-coupler. There is a delay of approximately 15 seconds before a change is recognized to avoid spurious switching. When AC is not available in AC only refrigerators, the message “no AC” is shown on the front display panel.

SectIon 4 dc Voltage

4.1 dc Voltage reQuIrementS

Clean Direct Current (DC) power is mandatory for hightech circuits to operate as designed. A battery will provide straight line DC power. The converter and alternator produce DC power by a series of diodes that rectify alternating current to DC. The Dometic control system will only tolerate up to 6 volts AC on the DC line (Also known as AC ripple). AC ripple can be measured by a digital voltmeter set on the AC scale and measured at the main DC terminal block connections at the back of the refrigerator. 6 volts AC or less is acceptable. If AC volts exceed 6 on the incoming DC line, the power source should be cleaned. AC voltage in excess of 6 volts will affect the processor and create erratic operation. When testing for AC ripple on the DC line put a load on the converter. The operational range of the unit is a minimum of 8.5 volts DC to a maximum of 18 volts DC (However 10.5 volts DC minimum is required to activate the defrost system). The unit will automatically shut down at 18 volts DC or greater, and come back on when voltage has decreased to the proper operating range. The refrigerator requires at least

8.5 volts DC for proper cooling operation. The refrigerator

must be connected to the battery circuit with two wires of adequate capacity to avoid voltage drop. Proper polarity is crucial for refrigerator operation. No other electrical equipment or lighting should be connected to the refrigerator circuit. Just because you can read volts, does not mean you have the amps to operate the control system. If relays buzz, lights go dim or out during operation, this could indicate there is a loose connection somewhere. As a last test, use a battery and run wires directly to the DC terminal block. If the unit works OK on direct DC voltage the problem is in the coach, not the refrigerator control system.

note: The defrosting cycle will not start if the voltage is

below 10.5 volts DC. It is important that the wires to the 12 volt DC terminal block are of proper wire size.

•

Check the wire gauge to ensure that it is in accordance with recommended dimensions.

length (ft) min. size (aWg) < 33 12 33-66 10 > 66 8

4.2 groundS

The operation of the Dometic refrigerator is also dependent on good, clean ground connections. Loose or corroded ground terminals create an unknown resistance factor that can affect the voltage detected by the Power Module. A loose negative DC wire will create a negative millivolt signal that the control board will pick up and create erratic operation. Check the integrity of the grounds from the refrigerator all the way to the power source/battery. Clean or tighten any suspicious looking connections.

Main Terminal Block

note: The DC terminal block located on the back of the

refrigerator should be cleaned and tightened at all four wires.

SectIon 5 dc comPonentS

5.1 door Switches and lamps

Both compartments have interior lights controlled by door switches. Both lamps are of a halogen type. The lamp in the freezer compartment is rated at 5 watts, while the lamp in the fresh food compartment is a 10 watt lamp. Lamps and switches are directly connected to the power module. The wires are foamed in and end up in the 10 pin Molex MiniFit P4 connector on the main circuit board. The lamps are directly controlled from the switches and the interconnections are on the main board. The processor on the power module cannot control the lamps but senses if the switches are closed or not, to decide if doors are open or closed (Used in the diagnostic mode). The door switches are open when the switch arm is depressed (interior light should be off). When the door is open the switch is closed (interior light should be on). Check that the switch assembly is properly aligned and that it is not broken. Check the switch assembly for continuity. To do a

continuity check, rst be sure all power is disconnected or

“OFF” to the refrigerator. Second, remove all wires from the switch assembly, then check the switch. When the switch is depressed, there should be no continuity. When the switch is NOT depressed, there should be continuity. If any of these checks are incorrect, replace the switch. After the check, be sure the switch assembly is wired properly per the wiring diagram.

1514

5.2 temperature Sensors

The NDA/NDE 1402 has two sets of thermistors. One for the freezer and the other for fresh food compartment. The display range is from - 9° F to 41° F in the freezer and from - 9° F to 59° F in the fresh food side. For temperatures below and above these ranges, the display will show “Lo” and “hi” respectively.

During normal operation, the temperatures in degrees Fahrenheit in the compartments are shown on the display, freezer to the left and fresh food to the right. However, the shown temperatures are not the ones actually measured. Instead they are calculated as the most probable temperatures of the food that is stored in the respective compartment. Therefore these temperatures should not be compared with temperatures measured with ordinary thermometers placed inside the compartments. When the power is switched “OFF” and then “ON” again, the temperature lters will forget historical values and the calculation restarts from the beginning. In this case the shown values will be about 2° F above the real air temperatures at the sensors.

Each thermistor harness consists of two thermistor sensors. One each for “air” and the other for “surface” for the defrosting process.

Disconnect the thermistor harness from the P2, 4-pin terminal (freezer) or P3, 4-pin terminal (fresh food) on the lower circuit board. Place the sensing tip in a glass of ice water (more ice than water), approximately 33° F to 35° F. Wait 8 to 10 minutes. You should get a reading of approximately 5,500 Ohms. Always test from the wire side of the 4-pin connector with the meter leads as not to create a connection problem at either the P2 or P3 connector.

note: A disconnected or faulty thermistor will result in an

error code displayed on the front display panel. See section 11 for trouble shooting error codes.

Fresh food air thermistor:

Remove the P3 connector from the lower control board. Check the resistance between pins 1 and 2 on the P3 connector.

Fresh food surface thermistor:

Remove the P3 connector from the lower control board. Check the resistance between pins 3 and 4 on the P3 connector.

Freezer air thermistor:

Remove the P2 connector from the lower control board. Check the resistance between pins 1 and 2 on the P2 connector.

Freezer surface thermistor:

Remove the P2 connector from the lower control board. Check the resistance between pins 3 and 4 on the P2 connector.

note: See page 49 for thermistor values at varying tem-

peratures.

5.3 low ambient control

The automatic Low Ambient Control ensures trouble free operation in low ambient temperatures (e.g. Below 50° F). In colder weather, the temperature inside the fresh food compartment tends to hold the temperature inside for a very much longer period of time, with very long periods in between ON/OFF cycling of the heat source; this is OK for any food product inside the fresh food compartment, but is not OK for the freezer compartment. The NDA/ NDE1402 have active thermostatic control of both compartments (however, you can only set the temperature level for the fresh food thermostat). If the temperature in the freezer is not low enough, the cooling is switched on. If the fresh food compartment then becomes too cold, the defrosting element will be switched on to keep it at the correct temperature.

Air sensor

4-pin connector

Surface sensor

5.4 frame Heater

The frame heater is located behind the metal frame between the doors. The heater helps to reduce sweating on the metal frame during periods of high humidity. The heater is on all the time except during the defrosting phases to reduce maximum current draw from the DC supply. To test the heater, remove the white wire from terminal (J4) and measure the resistance between the wire removed and chassis ground. You should have a resistance reading of 24 Ohms +/- 10%.

note: Some units may have a Light blue wire on J4.

5.5 Interior fans

5.6 thermo fuse

Both compartments have fans to help distribute the temperature evenly throughout the unit. These fans are DC operated and are connected directly to the lower power module. Both fans run continuous when the ON/OFF switch is in the “ON” position and the doors are closed. The fan in the fresh food side will run when the door is open, however the freezer side is stopped during opening of the door. The fans can be tested by applying DC power directly to the power leads.

The NDA/NDE 1402 cooling unit has a thermo fuse located on the boiler. The function of the thermo fuse is to shut down the control system in the event of a cooling unit problem. On certain units the fuse can be reset by pushing the button in the center. The thermo fuse is a non replaceable component of the cooling unit. When the fuse pops, it is normally an indication the cooling unit has a problem and the cooling unit will have to be replaced. To test the thermo fuse, check for continuity. Lack of continuity would indicate a faulty thermo fuse.

Thermo fuse

on boiler

Connection Block

Fresh food fan:

Remove the P4 connector from the lower control board. Apply 12 volts DC directly to pin 10 red wire (+) and pin 5 black wire (-). The fan should run. This test can also be performed at the terminal connection block just below the fan assembly. If the fan fails to run, it will need to be replaced.

Freezer fan:

Remove the P5 connector from the lower control board. Apply 12 Volts DC directly to pin 4 red wire (+) and pin 1 black wire (-). The fan should run. This test can also be performed at the inter-connection box along the back wall behind the ice maker assembly. If the fan fails to run, it will need to be replaced.

In order to prevent the circulation of warm air throughout the compartments and to reduce the current draw on the DC supply, both fans will be stopped after approximately 10 seconds if a source to heat the cooling unit is not available (e.g. No AC detection and failure to lite on gas “ch LP”) in the front display panel.

note: A disconnected or faulty fan assembly will result

in an error code displayed on the front display panel. See section 11 for trouble shooting error codes.

5.7 flame Sensing

The ame is detected by a method often called “ame rectication sensing”. A gas ame is slightly conductive

and by applying a voltage to the spark electrode, a small

current will ow through the ame to chassis ground. However, the ame conductivity depends on the polarity

of the applied voltage. A positive voltage on the electrode will result in a higher current than a negative voltage. This

“rectication property” of the ame is used to distinguish

it from leakage currents that could be caused by dirt or

moisture. To detect if a ame is present, a high frequency

AC voltage is applied between the burner and the electrode. This results in a net current in the forward direc-

tion if the ame is present, but no current if the ame is not present. The rectication property then causes that

the electrode will have a slightly negative DC voltage that is detected by the ignition control module. The AC voltage and the resulting negative voltage are not possible to measure with normal methods, as the impedance is too high.

1716

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

5.8 Ignition control module

The ignition control module supplies continuous DC voltage to the gas valve during gas operation. On gas operation the ignition control module senses the resistance

through the ame between the electrode and burner. When there is no ame at the burner, the resistance is

high and the ignition control module begins sparking to

light the burner. As soon as the ame is lit, the resistance

between the electrode and burner drops and the ignition control module stops sparking. The resistance is monitored by the ignition control module and, if for any reason

the ame goes out, the ignition control module begins

sparking until the burner is lit. The resistance between the electrode and burner drops and the ignition module

stops sparking. This insures that the ame will always be

lit when desired. First verify proper voltage at the Yellow (+) and White (–) terminals on the 4-pin connector of the ignition control module. This reading should be 8.5 volts DC or greater. Next, remove the high voltage cable from the ignition control module. The ignition control module should produce a sparking sound, during trial-for-ignition. If not, replace the ignition control module. While operation in the gas mode, the ignition control module is constantly

monitoring the presence of ame. If the ame is blown out,

the ignition control module will immediately start sparking.

When the ignition control module senses the loss of ame

(High resistance thru the electrode) the 45 seconds trial for ignition period is started.

The ignition control module has an additional ground strip wire underneath the left mounting tag. This wire must be in good contact with the metal frame of the burner assembly before the system is energized. Otherwise both the ignition control module and the power module may be damaged. At every gas operation request from the power module, the ignition control module performs an integrity test of the gas burning system. This test will detect if the system is operable or not. A message code will result in a lock out mode. “ch LP” will be displayed on the front display panel.

note: The message “ch LP”, for safety reasons will re-

main until the power is switched “OFF” and then “ON”.

5.9 electrode

Do a visual check for cracks, breaks or moisture on the ceramic insulator. A hair line crack can be hard to see at the electrode. The spark gap must be set at three sixteenths (3/16”) of an inch between the tip of the electrode and the slots in the burner. When adjusting, always loosen the screw and move into place. Never try to move without loosening the screw. On certain units the electrode and high voltage cable are integrated in to one component. To acquire the proper part always provide the product number of the model refrigerator you are working on.

High voltage cable to electrode

Leads from the main control board

Power leads to gas valve

5.10 High Voltage cable

If sparking starts during trial-for-ignition, the cable is good. If there is no sparking during trial-for-ignition, disconnect DC power at the refrigerator terminal block or switch the unit off. Disconnect the high voltage cable from the electrode. Reconnect DC power. If there is a sparking sound from the ignition control module during trial-for-ignition, then replace high voltage cable or electrode. On certain units the electrode and high voltage cable are integrated into one component. To acquire the proper part always provide the product number of the model refrigerator you are working on.

5.11 Solenoid

Check the solenoid coil with a properly calibrated Ohm meter. Remove the connectors from the solenoid and measure the resistance across the terminals. The proper reading would be 49 Ohms ± 10%. Failure of the solenoid is very unlikely. Next, hook up a manometer at the test port. Then check for DC volts at the gas valve terminals (Yellow +, White -) while the unit is in trial-for-ignition. If DC volts are present and the pressure is low, replace the valve. If DC volts are not present at the valve while the unit is in trial-for-ignition verify that terminal 2 (yellow wire) on the 2-pin connector from the ignition control module has DC volts (8.5 volts or more).

Depressions of the AUTO/STORE and SET buttons are interpreted by means of the display board processor, which then sends commands via a serial data bus down to the power module. The power module processor then executes the commands. The seven-segment displays are normally used to show the temperatures in the compartments. However, the temperature display may be in-

terleaved by means of ashing with a number of status

or error messages. During setting procedures (thermostat and clock settings) the displays are used to show setting information. The “decimal points” are positioned at the top of the display and these “points” are from left to right used to indicate PM at clock setting, AUTO mode, AC operation and GAS operation. The information displayed is controlled from the power module processor. When the fresh food door is closed, the display is dark. See section 11 for trouble shooting error codes.

5.12 front display Panel

The display module is the user interface and acts just as a slave to the power module. It has three buttons and four, seven-segment LED displays. The left most button is the ON/OFF button and is directly controlling the power mod-

ule. It has no direct inuence on the processor on board.

The button is not actually switching any current, but is just giving a signal on a separate wire down to the power module to switch the system “ON” or “OFF”. The button in the middle is the AUTO/STORE button. At normal operation this button is used to toggle energy selection modes between AUTO and MANUAL. This button is also used to store thermostat and clock settings during setting procedures. If this button is held down during power-up, a manually initiated defrost will start. The right most button is the SET button. It is used for thermostat and clock settings. If this button is held down during power-up, the service mode will be initiated.

Wire colors from top to bottom:

Black• Brown• Red• Orange• Green•

The NDA/NDE 1402 series display cable is identical to other cables, however the use of the wires are different. The display panel has no constant 12 volt DC supply and there is no voltage returning down to the lower control board. The ON/OFF feature is controlled by a momentary closing of a separate wire to ground when pressing the ON/OFF button. The upper display panel is always on, even if the refrigerator is off and is therefore capable of sensing the closing to ground.

Pin connections as seen at the lower board.

Pin 1, Green- ON/OFF Control (momentary closes

•

to ground when pressing the ON/OFF button). Pin 2, Not Connected.• Pin 3, Black- (+12) volt DC supply to the display • board when the refrigerator is on. Pin 4, Orange- Not Connected.• Pin 5, Red- Ground.• Pin 6, Brown- Communication Line.•

1918

tyPIcal WIrIng dIagram

nda 1402

tyPIcal WIrIng dIagram

nda 1402

2120

5.13 lower Board

The power module is the main control unit that acts as the heart of the electronic control system. It performs power ON/OFF control, energy selection, thermostatic operation control and defrosting control. All other electrical parts are connected to the power module. See section 11 for trouble shooting any error codes.

all teStS are to Be done WItH tHe refrIgerator In tHe coolIng mode.

unplug both thermistors from the control board during lower board testing to assure the unit is calling for cooling.

dc Volts

Measure the DC voltage between terminal (J2) positive (+) and (J1) ground (–) on the main control board. The voltage should be the same as at the positive (+) and negative (–) terminals on the DC input terminal block. 8.5 volts minimum to 18 volts maximum would be the operating range. If the voltage is outside the 8.5 volts minimum to 18 volts maximum, check the power supply, terminal block and correct the power source before going on with the test.

ac mode

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

Verify that the following components are good: upper circuit board, thermistor, wire harness and 3-amp fuse (F2). First, check for voltage during trial-for-ignition at Plug P6, Terminal 2 (yellow wire +) to the ignition control module. If no voltage is present change the main circuit board. If voltage is present and there is no spark, test the ignition control module. See section 5.8 for diagnosis.

note: A loose ground will create erratic or no gas op-

eration on all systems. Tab connectors from left to right (at the bottom edge of the

main control board)

•

J1- is the ground (–) connection. J2 is the 12 volt DC (+) battery voltage input into • the power module. J3 and J4 are connected in parallel and are sup-• plying 12 volt DC (+) to the door frame heater and the anti-freezing system for the ice maker water supply line. J5- is the DC voltage output to the defrosting ele-• ment in the freezer. J6- is the 120 volt AC neutral connection for the • ice maker. J7- is the 120 volt AC main supply neutral con-• nection. J8- is the 120 volt AC neutral connection for the • AC heaters in the cooling unit. J9- is the 120 volt AC main line connection for the • AC heaters in the cooling unit. J10- is the 120 volt AC main supply line connec-• tion. J11-is the 120 volt AC line voltage to the inter-• face module if using a single power cord.

If the unit has a separate power cord for the ice-maker, (J6) and (J11) will not be used.

Test the upper control board and the 5-wire harness before testing for proper AC operation. Check that the incoming AC voltage is present between terminals J10 (black) and J7 (white) on the lower circuit board. If no voltage is present, check wiring and the coach power supply. If voltage is present, and with the unit on AC operation, check for voltage at the heating element connection terminals (J8) and (J9) on the circuit board. If no voltage is present, disconnect 120 volt AC and 12 volt DC and check the 5 amp AC (F5) and 3 amp DC (F2) fuses, wiring harness and upper control. If AC volts are present between (J7) and (J10), and no voltage on (J8) and (J9) the AC voltage detection circuit is damaged and the control board will need to be changed.

gas mode note: All current Dometic control boards are 3 try sys-

tems in the gas mode. There is a 2 minute purge cycle between each trial for ignition. Flame failure could take 6 to 7 minutes.

5.14 fuses

The NDA/NDE 1402 use (4) DC fuses to protect the circuit board from internal/external DC shorts. The 5 amp AC (glass) fuse is designed to protect the integrity of the AC detection and heater circuit from shorts. All fuses should be checked for continuity with the fuse removed from the board. If a fuse blows don’t replace it, until the problem has been found. If a fuse blows there is a short or component that has created the problem.

Fuses (From left to right, on the lower board)

fuse type of component

(F2) 3 amp A, B, C, E, G, H, P, R (F6) 7.5 amp S, T (F3) 3 amp W (optional icemaker kit) (F4) 7.5 amp X (F5) 5 amp Z

Always refer to the wiring diagram for the model/product number to determine the “Type of component” designation.

SectIon 6 lP gaS

lP gaS reQuIrementS

DO NOT use a ame to check for gas leaks.

The LP gas pressure to the refrigerator should be 11 inches water column with half of all BTU’s of the RV turned on. With all other appliances off, the pressure to the refrigerator should not exceed 12 inches water column. To check the gas pressure when the refrigerator is operating, there is a pressure test port below the solenoid valve assembly. Use a calibrated manometer to check for proper gas pressure.

SectIon 7 lP gaS comPonentS

7.1 manual gas Shutoff Valve

The manual shutoff valve is a non-serviceable part. The valve is part of the solenoid valve assembly. It is very rare to have problems with the manual shutoff or the solenoid assemblies. If you have checked gas pressure and it’s low, check the pressure at the input line to the refer. If the pressure is 11 inches at the input and low at the pressure test port, change the solenoid valve assembly. The valve in not opening all the way.

No bubbles should appear at the opening of the

•

burner jet orice. The presence of bubbles indi-

cates a defective gas safety shutoff, and service is required. If no bubbles were present at the burner jet ori-•

ce, it should be rinsed with fresh water. Be care-

ful not to damage the burner jet orice. Replace

the cover and press the main power ON/OFF button “OFF” and back “ON”. Normal operation of the burner should return. Allow the burner to

operate for a minimum of ve minutes.

7.2 Orice

The Dometic orice is a brass alloy with a man-made ruby

pressed in the center that has been laser-beam drilled in

a spiral pattern. The orice is cleaned by using an alco-

hol based solvent. Soak the orice for approximately 1

hour and allow to air dry. do not insert anything into

the center of the orice as it can damage the man-made

ruby. do not use an air nozzle to blow thru the orice as the ruby could be moved or damaged. Never over or un-

der size the orice on a Dometic refrigerator. The cooling

unit is designed to work with a predetermined amount of

heat and modifying the orice size will decrease cooling.

If there is a lack of cooling on gas operation, verify the

orice is the proper size per the chart.

teStIng lP gaS Safety SHutoff

The gas safety shutoff must be tested after the refrigerator is connected to the LP gas supply. To test the gas safety shutoff, proceed as follows:

•

Start the refrigerator according to the instructions, and switch to the GAS mode.

Check that the gas ame is lit and the GAS mode •

indicator lamp is on. Close the manual gas shutoff valve at the back of • the refrigerator. Wait for six to seven minutes. The “chLP” indi-• cator should be on and the GAS mode indicator lamp should be off. Remove the protection cover from burner and • open the manual gas shutoff valve. Do not change any button positions on the control panel. Apply a non-corrosive commercial bubble solution to the

burner jet orice.

do not use a wire or pin when cleaning the burner jet as damage can occur to the precision opening. this can cause damage to the refrigerator or create

a re hazard.

model Jet Size

NDA 1402 #76 NDE 1402 Not Used (All Electric)

Always check the parts list with the model and product number to assure the right jet size.

2322

7.3 Burner

The burner is a slotted metal tube located below the ue

tube on the cooling unit. It should be level and the slots

in the burner should be directly below the ue tube. The

burner should be cleaned periodically, at least once a year. To clean the burner, remove from the refrigerator and check for any foreign residue that could cause a de-

ection of the gas ow or the ame. Next, soak the burner

in an alcohol based solution and allow it to air dry. If the burner does not have a good ground it can cause erratic gas operation. The electrode sparks to the burner tube and an erratic ground will cause erratic gas operation.

7.4 Flue Bafe

The ue bafe (spiral bafe) is a twisted piece of metal that hangs in the ue tube to slow the heat from the ame to the proper location on the cooling unit. If the ue bafe

is too high or low the heat will not be transferred to the cooling unit properly. It should be cleaned periodically, at

least once a year. To clean, remove from the ue tube and

check for any damage, then clean thoroughly.

7.6 flue tube

The ue tube is a component that is welded to the pump

tube of the cooling unit. It must be cleaned periodically, at

least once a year. To clean, remove the ue cap (if appli-

cable) and ue bafe, then cover the burner and clean by using a ue brush, Dometic Part Number 0151404001. If the ue tube becomes coated with scale or residue from

combustion of LP gas, the efciency of gas operation de-

creases.

SectIon 8

Bafe

model above the

Size

Burner

NDA 1402 1-1/4” 6” x 15/16” NDE 1402 Not Applicable Not Applicable

Lack of heat transfer to the cooling unit will cause low cooling performance in the gas mode. It should be cleaned periodically, at least once a year. The proper position of

the bafe above the burner should be as shown in the

chart: always refer to parts list on the model/product number unit you are currently working on.

7.5 flue cap

The ue cap is located at the top of the ue tube and is

attached with a screw or pushed down over tube. Not all

units will come with a ue cap. The design of the bafe wire in the ue tube will slow down a down draft.

coolIng unIt

8.1 cooling unit

The cooling unit is a self-contained, hermetically sealed set of coils where the refrigeration process takes place. The chemicals involved in the cooling process include hydrogen, ammonia, water and a rust inhibiting agent. There are no repairs recommended on the cooling unit. If it is defective, replace with a new cooling unit. To check

the cooling unit, rst verify the AC heating elements are

good. Verify for proper Ohms at room temperature. Also verify for proper venting and the unit is level. Then place approximately one gallon of water inside the refrigerator and place a thermometer in the container of water. Next, unplug both thermistors from the lower control board. This will by-pass the thermostat control and operate for at least 12 hours. Then check the temperature on the thermometer. It should be at 43 degrees or lower depending on test conditions. If so, the cooling unit is good. If the temperature of the water is above 43 degrees, replace the cooling unit. The outside temperature will affect the cooling capacity of the unit. There is that rare occasion when the

cooling unit will work OK for the rst 12 hours and start to

warm up. If the customer’s complaint is “works OK for 2 to 5 days and then warms up”, the unit may have an internal problem. To test this it would be necessary to operate the cooling unit for up to 24 to 48 hours in the test mode.

2524

8.2 Ventilation

The installation shall be made in such a manner as to separate the combustion system from the living space of the mobile home or recreational vehicle. Openings for air supply or for venting of combustion products shall have a minimum dimension of not less than 1/4 inch. Ventilation is a critical requirement for proper cooling unit operation. The coach vent system must be able to provide a way to direct the hot air, produced by the action of the cooling unit, out away from the installation of the refrigerator. The refrigerator extracts heat from the interior of the refrigerator cabinet and dissipates the heat out through the vent system. In a proper installation there should be zero (0”) clearance surrounding the sides and top of the

refrigerator to achieve proper air ow. Clearance from the

back of the refrigerator to the outside wall must be kept no greater than 1 inch. All potential dead air pockets should

be blocked or bafed to ensure that heat won’t be trapped in these spaces and reduce efciency.

note: Refrigerators should be installed in accordance

with appropriate installation instructions received with the refrigerator.

for more uPdated InformatIon on unIQue VentIlatIon reQuIrementS, refer to Vent Installa-

tion Instructions, Form No. 3308666.XXX.

typical roof Vent and Side Wall Vent

Some unIQue aPPlIcatIonS may reQuIre tHe InStallatIon of an aIr cHannel KIt; refer to Air

Channel Kit Installation Instructions, Form No. 3312374. XXX.

Baffle

typical two Side Wall Vents

turnIng Vane

Baffle

typical two Side Wall Vent application. always refer to Vent Instructions 3308666.xxx

(Dimensions are in inches)

Model No.

Min. Vent Height

Min Dim. +1/4, -0

Min Dim.CMax

Dim.

Min Dim.D*Max

Dim.

NDA 1402 63 27 - 1/16 5 - 1/8 8 4 - 5/8 1 44 - 1/2 NDE 1402 63 27 - 1/16 5 - 1/8 8 4 - 5/8 1 44 - 1/2

E F

* When dimension “D” exceeds “1”, it is necessary to add bafe (E) above lower access vent as shown, for more efcient operation in

warm temperatures.

tHe fan Placement dImenSIon to tHe refrIgerator floor muSt Be maIntaIned eVen WHen tHe uPPer Vent IS located HIgHer tHan dImenSIon “a”

2726

8.3 Ventilator fans

8.5 food Storage

The NDA/NDE 1402 models use two ventilator fans mounted to the back of the refrigerator (exterior). The purpose is to assist required air movement across the refrigerator condenser to ensure optimum performance. The fans are powered from DC current and are controlled from a limit switch, mounted on the end plate to the condenser

ns just above the ue. The limit switch is normally open

and will close at 149° F +/- 9° F and re-open at 122° F +/9° F. The switch can be checked for continuity. If the fans fail to run. Check all wiring, the inline 3 amp fuse and the limit switch. If these checks are good, replace the fan(s).

8.4 leveling

Leveling is one of the requirements for proper operation of absorption refrigerators. The absorption design utilizes no mechanical pumps or compressors to circulate the refrigerant within the system, so proper leveling must be maintained to provide the correct refrigerant ow. Without proper leveling, refrigerant within the cooling unit will collect and stagnate at certain areas. Without proper re-

frigerant ow, the cooling process will stop. Absorption

refrigerators have a type of cooling unit that utilizes an enclosed pump tube surrounded by a solution to protect the assembly. To ensure proper leveling, the vehicle needs to be leveled so it is comfortable to live in. (No noticeable sloping of oor or walls). When the vehicle is moving, leveling is not critical as the rolling and pitching movement of the vehicle will pass to either side of level, keeping the refrigerant from accumulating in the piping.

Perfectly leVel not reQuIred more leVel = Better oPeratIon

Proper refrigeration requires free air circulation within the food storage compartments. Restricted air circulation within the compartments will cause higher cabinet temperatures. To remedy this situation, simply rearrange your foodstuffs. It is also essential that the shelves are not covered with paper or large storage containers. Always remember to allow for proper air circulation. Odorous or

highly avored foods should always be stored in covered

dishes, plastic bags or wrapped in foil or waxed paper to prevent food odors. Vegetables, lettuce, etc., should be covered to retain their crispness.

neVer Put Hot food Into tHe refrIgerator.

To reduce frost formation in and on the freezing compartment, cover stored liquids and moist foods and do not leave the door open longer than necessary. When the refrigerator is heavily loaded, it takes a longer time for refrigerator temperatures to lower, also increasing the ice making time.

8.6 ambient temperature

This is the temperature surrounding the recreational vehicle, as well as the temperature of air at the back of the refrigerator. As the ambient temperature increases, the air temperature in the area of the cooling unit increases. Improper venting at this point will cause the cooling unit

to have reduced efciency. A refrigerator that chases the

out-side temperature is improperly vented or a weak cooling unit.

Section 9 froSt

9.1 door Seals

Check the gasket on the doors to be sure of a positive air seal. A simple method to check gaskets is to close the door on a dollar bill, then pull the dollar bill out. If no resistance is felt, the gasket in that location is not sealing properly. This should be done on all sides of the door in several places. If a gasket is not sealing properly, lift up

the inside of door gasket and insert 1/4” ball of berglass

insulation at all corners on both doors. This is especially important to the top corners. Next, warm the gasket material with a hair dryer. Then close the door and the magnetic strip should pull the gasket to the metal frame. Leave the door closed until the material has cooled. Then recheck for a positive seal. If a positive seal cannot be achieved, replace the door gasket. Also check that the cooling unit is installed properly. The cooling unit’s foam block, the

portion that surrounds the evaporator coils, must be ush

to the cabinet at the back of the refrigerator and have a positive seal. If the cooling unit is not installed properly, remove and install properly.

NOTE: Air leaks will cause insufcient cooling as well

as rapid formation of frost.

do not oVerHeat gaSKet

aS you can melt tHe materIal

9.2 Interior liner Seal to frame

There is a seal that is applied to the liner in the area where the metal frame makes contact with the interior liner. If this seal is incomplete, cold air can migrate out to the metal frame. If this happens, condensation could form on the frame and could promote rapid formation of frost. If you suspect an improper seal, apply a small bead of silicone all the way around the perimeter where the frame meets the interior liner. Next remove all screws securing the refrigerator into the cabinet and slide the refrigerator out approximately 2–4 inches. Clean the metal frame and foil-backed insulation around the refrigerator. Apply a foilbacked adhesive tape to the joint between the outer frame and the foil-backed refrigerator insulation. Make sure the refrigerator is dry and that the surface temperatures are above 50° F. Use a white silicon caulking compound and seal the seam between the refrigerator’s plastic liner and the metal frame. Apply the silicon in a continuous bead around both the freezer and fresh food compartments.

For freezer doors not sealing at the angled portion of the door, replace the sealing strip mounted under the gasket. For refrigerators lacking this strip, contact Dometic Technical Services and ask for part# 385133501.

caulK Seam BetWeen PlaStIc lIner and metal frame

(r e fr i ger a to r shown with doors removed)

note: to form a proper seal, it is important not to

leave any gaps

aPPly foIl-BacKed or alumInum taPe to tHe JoInt BetWeen tHe outer frame and tHe foIlBacKed refrIgerator InSulatIon. go around tHe comPlete frame.

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9.3 drain tube

The drain tube is used during the defrost cycle to allow water from the defrosting of the freezer section to migrate to the fresh food side and be drained through the rear of the refrigerator and out through the oor or the lower sidewall vent. The drainage tube must be free from anything

blocking the passage. The required orice dimension is

1/4”. Check the drainage tube for blockage, ice, dirt etc.

and clean if necessary. If the orice dimension is smaller than 1/4”, use a sharp tool to increase the orice size.

Check orice diameter. Should be ¼”

Wire harness

Ice maker ll tube

and wire harness

Locate the drain plug at the bottom rear of the freezer compartment. Make sure the drain plug is in place. If the plug is missing, install with a new one.

Another source for air leaks could be the drain hose. At the end of the drain hose is a check valve. During installation of the refrigerator the hose might be shortened and the check valve must be moved to the end of drain hose. Any time lack of performance or excessive frost is experienced, look for the check valve at the end of hose.

9.4 Wall entrances

To prevent air leaks from the outside, it is vital to make sure that wall entrances have been sealed properly and that the drain plug is inserted at the bottom rear of the freezer compartment.

Verify that the wall entrances for the wire harnesses and

for the ice maker ll tube have been sealed properly. If

necessary, apply a butyl tape type sealant around the openings from the inside as well as from the outside.

In most applications, removing the upper side wall vent will access the entrance points. For applications using a roof vent, removal of the refrigerator may be necessary.

Drain plug at bottom rear of freezer compartment

9.5 auxiliary defrost fan

In some cases refrigerators with serial numbers below 707XXXXX may require an auxiliary defrost fan kit to be installed to reduce the formation of frost in the freezer section. Contact Dometic Technical Service at 800-216-5115 to order an auxiliary defrost fan kit (Part# 385130901). The Refrigerator must be completely defrosted before repairs are completed to ensure proper operation.

9.6 High Humidity

If the interior of the coach is not air conditioned, higher temperatures and humidity can occur. A small amount of condensation may form on the frame of the refrigerator or around the ice dispenser area. In some cases it can develop to such a degree that it will run off the frame or down the freezer door. As the humidity is reduced, the sweating will decrease. High humidity can also be a factor in rapid formation of frost.

9.7 door Position

If either door is closing too high or low against the frame,

cold air leakage can occur. Adding or deleting a at thin

washer at the top or lower hinge pin can raise or lower the door position. To correct the door alignment, loosen the hinge screws slightly and reorient the door in the proper position. Hold the door in its new position and carefully retighten the hinge screws.

SectIon 10

Heating in the freezer

defroStIng

10.1 real time clock

To get the best performance from the refrigerator, defrosting is performed when the least amount of demand is on the refrigerator. Therefore the refrigerator has a real time clock that controls the defrosting process. The clock runs even if the refrigerator is switched “OFF”. However, if the 12 volt DC supply (battery voltage) is disconnected, the clock will continue to run only about three weeks. So if the battery voltage has been disconnected for more than three weeks, the clock must be set again. This will be indicated by horizontal bars (- - - -) in all four, seven-segment displays. Even if this “clock not set” warning is not shown, the clock should be checked at regular intervals (at least once per year) to ascertain that the time setting is correct. It is also recommended to reset the clock when entering different time zones. (Refer to section 1, page 11 for setting of the clock).

10.2 automatic defrosting

There is a blocking function that inhibits automatic de-

frosting during the rst 24 hours after the refrigerator is

switched “ON”. This 24 hour blocking function is reinitialized every time the refrigerator is switched “OFF” for more than one hour. Defrosting is initiated automatically every 24 hours, at 1:00 AM ( based on clock setting). However, a defrosting may be skipped if the air temperature in the freezer is greater than 18° F, or the DC voltage is less than 10.5 volts.

note: An automatic defrost may also be skipped if the

control module detects a fault with either the heater or the thermistor for the cooling surface in the freezer section. These conditions will be indicated by an error code displayed on the front display panel. See section 11 for trouble shooting error codes.

The start of an automatic defrosting may be delayed for up to 3 hours based on two criteria. If the battery voltage is lower than 10.5 volts DC, or no cooling source (Gas or Electric) is available. If these two conditions are met, the defrost will be started and will complete as normal. If these two conditions are not met within 3 Hours, the defrost for this 24 Hour period will be skipped, and recorded as incomplete.

temperature “pull down”

After the relaxing period, the heating elements in the freezer and in the water drain are switched “ON”. The fan in the freezer is at the same time stopped to prevent the food from being heated by hot air.

The heating stops when the temperature on the cooling surfaces has reached 41° F or when 75 minutes has elapsed. If the heating is stopped by the time criteria, the defrosting is treated as incomplete. An incomplete defrosting could depend on either extreme ice on the cooling surface, or that the battery voltage has became so low that the heating effect was insuf-

cient.

The heating is also stopped before the defrosting is completed if the battery voltage drops below the battery protection level (less than 8.5 volts DC).

Heating in the fridge

After the defrosting of the freezer, the cooling unit is restarted again. It takes some time before cold is produced and during that period, the defrosting in the fridge now takes place. After a one minute delay, the heating element in the fridge is switched “ON”. The fan in the fridge is stopped during this defrosting cycle. The heating element in the water drain line remains “ON”.

The heating stops when the temperature on the cooling surfaces has reached 41° F or when 20 minutes has elapsed. If the heating is stopped by the time criteria, the defrosting is treated as incomplete. An incomplete defrosting could depend on either extreme ice on the cooling surface, or that the battery voltage has became so low that the heating effect was insuf-

cient.

The heating is also stopped before the defrosting is completed if the battery voltage drops below the battery protection level (less than 8.5 volts DC).

After the defrosting of the fresh food side, normal thermostatic operation is restarted again. However, the heating element in the water drain line is still “ON” for some time. It is switched “OFF” 30 minutes after the start of the fresh food defrosting period.

When a defrosting is initiated, the rst thing that happens is that the refrigerator pulls down the compartment temperatures to thermostat “cut out” levels. If these levels are not reached within one hour, the defrosting sequence starts anyway.

cooling unit relax time

After the temperature pull down period, the real defrosting sequence is started. The cooling unit is now switched “OFF”, but nothing more happens for 10 minutes to let the cooling unit relax.

If 2 incomplete defrostings occur in a row, the warning message “Er 01” is displayed on the front display panel.

note: The WARNING “Er 01” on the front display

panel indicates that 2 or more consecutive defrosting attempts failed. This message will disappear when a defrosting has completed successfully. But it will also be cleared if the power is switched “OFF” and then “ON”.

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freezer fan operation during and after a defrosting

The fan in the freezer is stopped during defrosting of the freezer cooling plate, but it is started for short periods of time for testing and to prevent it from being blocked (Test and Rinse). A permanently blocked fan will display a message “Er 02” on the front display panel. This message is also shown if the fan is permanently blocked during normal thermostatic operation.

After a defrosting, the fan in the freezer is not started until the temperature on the cooling surfaces becomes colder than the air temperature in the freezer.

note: The warning “Er 02” on the front display panel

indicates that the fan in the freezer is blocked (by ice probably). As soon as the fan can move again, this message disappears. The fan has to be blocked for at least one hour before this message is shown. When the fan is “OK” it will only be a delay of about one minute before the message is cleared.

Power breaks during a defrosting

If the 12 volt DC supply is removed for short periods of time or if the refrigerator is switched “OFF” and then “ON” again during an automatic defrost, the defrosting will continue from the point where it was interrupted. However, if power has been “OFF” for more than one hour, the remaining part of the defrost is skipped.

cancelling of an automatically initiated defrosting

If, for some reason an automatically initiated defrosting needs to be cancelled, enter the “Service mode”. Then switch the refrigerator “OFF” and then “ON” again. This cancelling will not work immediately after the defrosting is initiated at 1:00 AM. Wait at least three minutes before trying to cancel the defrosting.

10.4 drying function

When the NDA/NDE 1402 refrigerator is to be off for some time, the compartments must have a chance to dry up to prevent mold from forming. The doors should then be left open. However, the cooling surfaces in the freezer will dry very slowly as they are well encapsulated and the air convection is small. Therefore the refrigerator has a feature that can speed up the drying of the freezer. To initiate this drying function, start the refrigerator with the AUTO/ STORE button held down and the freezer door open. If required, the drying function starts with a defrosting. The drying period will take about 3 hours (longer if a defrosting is rst performed). Afterwards the refrigerator is automatically switched off. The drying function may be terminated by switching off the refrigerator or by closing the freezer door.

note: Not all NDA/NDE 1402 models will have this fea-

ture.

10.5 freezer defrost Heating element

The freezer heating element is a coated heat lm, taped to the back side of the cooling ange. This ange is not

visible when opening the freezer door. It is enclosed behind a cover mounted to the upper right hand side of the freezer. During the cooling cycle, as the plate gets cold the chilled air is directed into an air channel and pulled to the lower section of the freezer by the fan assembly. During defrosting, the heater will provide 70 watts of heat to melt the ice or frost that has accumulated on the cool-

ing ange. To check the resistance of the freezer heating

element, remove the cover of the main control board on the back of the refrigerator. Remove the red wire from terminal (J5). Measure the resistance between this wire and ground (-). The resistance reading should be 2 Ohm’s +/- 10%. The resistance can also be checked at the interconnection box along the back wall behind the icemaker assembly. The refrigerator should be defrosted prior to this test to avoid erroneous readings. Frost/Ice could conduct current hiding an open circuit in the heater. A faulty heater may display an error code on the front display panel. See section 11 for trouble shooting error codes.

10.3 manual defrosting

A manually initiated defrosting will start if the AUTO/ STORE button is held down during “power up”. However, on some models, if the freezer door is open during this initiation, a drying up period is instead started. A manually initiated defrosting is identical to an automatically initiated defrosting with the exception that the defrosting sequence starts immediately with the “relaxing period”, that is without any initial temperature “pull down” period. A manually initiated defrosting may be cancelled at any time just by switching the refrigerator “OFF” and then “ON” by means of the ON/OFF button. However, a short 12 volt DC power break will not cancel the defrosting.

Another test would be to check the amp draw. A simple method is to remove the wires from the thermo fuse and place a meter inline. Enter the service mode, and proceed to test #8. The amp draw should be 5.8 +/- 10%.

note: The interior light must be off when performing

this test as to avoid a false value of the actual amp draw of the heater.

10.6 fresh food defrost Heating element

The fresh food heater is located behind the cooling ns

along the back wall of the refrigerator section. When activated, it will provide 40 watts of heat to melt any ice or frost that may have accumulated during normal operation. To check the resistance of the heater, remove the cover from the main control board on the back of the refrigerator. Remove the P5 harness cable from the lower pc board. Measure the resistance between pin 6 (red wire) and pin 3 (black wire). The resistance reading should be

3.6 Ohm’s +/- 10%. The resistance can also be checked

at the inter-connection box just above the cooling ns.

The refrigerator should be defrosted prior to this test to avoid erroneous readings. Frost/Ice could conduct current hiding an open circuit in the heater. A faulty heater may display an error code on the front display panel. See section 11 for trouble shooting error codes.

Drain tube/tray heater installed.

Drain tube/tray heater removed

Another test would be to check the amp draw. A simple method is to remove the wires from the thermo fuse and place a meter inline. Enter the service mode, and proceed to test #7. The amp draw should be 3.3 +/- 10%.

note: The interior light must be off when performing

this test as to avoid a false value of the actual amp draw of the heater.

10.7 drain tube/tray defrost Heating ele-

ment

The drain tube/tray heater is placed at the bottom of the plastic cover, housing the freezer cooling plate. This heater is on at all times during the defrosting of the freezer and fresh food compartments and will remain on for short periods of time at the end of defrosting to help assure water does not refreeze in the drain line. To check the resistance of the heater, remove the cover from the main control board on the back of the refrigerator. Remove the P5 harness cable from lower pc board. Measure the resistance between pin 5 (white wire) and pin 2 (yellow wire). The resistance should be 13.3 Ohm’s +/- 10%. The resistance can also be checked at the inter-connection box along the back wall behind the ice maker assembly. The refrigerator should be defrosted prior to this test to avoid erroneous readings. Frost/Ice could conduct current hiding an open circuit in the heater. A faulty heater may display an error code on the front display panel. See section 11 for trouble shooting error codes

In some cases during the install or replacement of the drain tube/tray heater, the portion that extends into the drain tube may become folded over or bunched up. When the heater is activated, this may cause a short and cause the heater to become open. A faulty heater may display an error code on the front display panel. See section 11 for trouble shooting codes.

Verify the portion extending into the drain tube is not looped or folded over to itself.

Another test would be to check the amp draw. A simple method is to remove the wires from the thermo fuse and place a meter inline. Enter the service mode, and proceed to test #9. The amp draw should be .9 +/- 10%.

note: The interior light must be off when performing

this test as to avoid a false value of the actual amp draw of the heater.

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SectIon 11 trouBle SHootIng

11.1 Status messages

Only one error code is displayed at a time. If more than one error exists, the error with the lowest • error number is shown. Some errors are only detected at the power ON self-test; others are detected all the time and will • be shown as soon as they occur. Therefore some error messages may not be reset until the refrigerator is turned “OFF and then back “ON”.

led display Panel Status message Steady display flashing-

(alternates between

temp. & message)

“dE Fr” Defrost has been initiated. X “drY” Drying phase has been initiated. X

“x” (1-5) Thermostat range set point. (1-5) X “ch LP” Gas operation fault. [1] (NDA 1402 only) X “ch AC” A/C operation fault. [2] (NDE 1402 only) X “Lo dc” Voltage is too low to start defrosting. [3] X “-- --” Real time clock needs to be set. [4] X “Er 01” Defrosting problem; (Two incomplete de-

frost attempts failed consecutively). [5]

“Er 02” The fan in the frozen food compartment is

blocked. [6] “Er 03” Freezer plate is above 95° F. [7] X “hi” Temperature is above measurement range.

[8] “Lo” Temperature is below measurement range.

[9] “CA LL” and a error code Component failure. [10] X

[1]

Check to make sure that the LP-gas supply tanks are not empty and all manual shutoff valves in the lines are open. If

the refrigerator has not been in used for a long time or if the LP tanks have been recently relled, air may be trapped

in the supply lines. To purge the air from the lines may require resetting the ON/OFF button several times. Check the AC supply, fuses etc.

[2] [3]

Check battery charge level (min 10.5 volts DC).

[4]

Refer to section 1, page 11 for setting of the clock.

[5]

Defrosting has been insufcient twice in a row (48 hours) either because of the DC voltage being too low, no cooling

source available or because of too much frost buildup. Check the battery charge level to overcome low DC voltage situations. Check for the proper wire size as described in the table on page 14. Use the manual defrost function (see page 11) to overcome excess of frost buildup.

[6]

The fan in the freezer has been blocked and is not circulating the air in the freezer compartment. Check the fan by unscrewing the bottom part of the fan housing. Try to rotate and look for ice buildup or other parts that can interfere with the rotation of the fan.

[7]

The temperature of the cooling plate in the freezer is above 95° F when you start a “drying” phase. It is shown for one minute and then the refrigerator is turned off. This is a protection function against overheating if you try to start a “drying” phase just after a “drying” phase has been performed.

[8]

The compartment temperatures are warmer than 41° F in freezer and warmer than 59° F in fresh food compartment. The compartment temperatures are less than -9° F in freezer and less than -9° F in the fresh food compartment.

[9]

Refer to section 11.2, page 34 for troubleshooting the error codes.

[10]

11.2 error codes

NEA1402

Error codes are shown ashing, alternated with the message “CALL”.

fault detected message displayed

Defrost heater for the freezer plate is faulty. “Er 11” Defrost heater for the fresh food cooling ange is faulty. “Er 12” Defrost heater for the drain tube/tray heater is faulty. “Er 13” Fan in the freezer compartment is faulty. “Er 14” Fan in the fresh food compartment is faulty. “Er 15” Air temperature sensor in the freezer compartment is faulty. “Er 16” Air temperature sensor in the fresh food compartment is faulty. “Er 17” Surface temperature sensor in the freezer compartment is faulty “Er 18” Surface temperature sensor in the fresh food compartment is faulty. “Er 19”

NDA1402

“Er 11”:

The fault is detected as an “open circuit” to the heating element for defrosting of the freezer plate.

Possible faults:

Blown Fuse F4 (7.5 amp).

•

Cable on terminal (J5) on the lower control board • is disconnected. Ground cable to the heating element, terminal • (J1) on the lower control board is loose. Wrong or loose connections in the inter-connec-• tion box inside the freezer compartment. Blown overheating protection fuse in the heating • element (heating element has to be replaced). Broken element (heating element has to be re-• placed). See section 10.5 for testing of the heater.•

“Er 12”:

The fault is detected as an “open circuit” to the heating

element for defrosting of the fresh food cooling ange.

Possible faults:

Blown fuse F6 (7.5 amp).

•

Connector (P5) on the lower control board is dis-• connected. Loose wires in the harness connected to (P5).• Wrong or loose connections in the inter-connec-• tion box inside the fresh food compartment. Blown overheating protection fuse in the heating • element (heating element has to be replaced). Broken element (heating element has to be re-• placed) See section 10.6 for testing of the heater.•

“Er 13”:

The fault is detected as an “open circuit” to the heating element in the drain tube/tray heater.

Possible faults:

Loose wires in the harness connected to (P5) on

•

the lower control board. Wrong or loose connections in the inter-connec-• tion box inside the freezer compartment. Blown overheating protection fuse in the heating • element (heating element has to be replaced). Broken element (heating element has to be re-• placed) See section 10.7 for testing of the heater.•

The fuse F6 also serves this heating element, but if the fuse is blown “Er 12” will be shown, as it has priority over “Er 13”.

“Er 14”:

The fault is detected as an “open circuit” to the fan in the freezer compartment.

Possible faults:

Loose wires in the harness connected to (P5) on

•

the lower control board. Wrong or loose connections in the inter-connec-• tion box inside the freezer compartment. Wrong polarization at the fan terminal block. • Fan motor faulty. • See section 5.5 for testing of the fan.•

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“Er 15”:

The fault is detected as an “open circuit” to the fan in the fresh food compartment.

“Er 19”:

The fault is detected as an “open circuit” to the surface temperature sensor in the fresh food compartment.

Possible faults:

Loose wires in the harness connected to (P4) on

•

the lower control board. Wrong or loose connections at the screw termi-• nal block inside the fan housing in the fresh food compartment. Wrong polarization at the fan motor terminal • block. Fan motor faulty. • See section 5.5 for testing of the fan.•

“Er 16”:

The fault is detected as an “open circuit” to the air temperature sensor in the freezer compartment.

Possible faults:

Connector (P2) on the lower control board is dis-

•

connected. Loose wires in the harness connected to (P2) on • the lower control board. Broken air temperature sensor in the freezer • compartment. See section 5.2 for testing of the temperature • sensor.

Possible faults:

Loose wires in the harness connected to (P3) on

•

the lower control board. Broken surface temperature sensor in the fresh • food compartment. See section 5.2 for testing of the temperature • sensor.

note: A disconnected (P3) connector will result in an

error code 17 as this has priority.

“Er 17”:

The fault is detected as an “open circuit” to the air temperature sensor in the fresh food compartment.

Possible faults:

Connector (P3) on the lower control board is dis-

•

connected. Loose wires in the harness connected to (P3) on • the lower control board. Broken air temperature sensor in the fresh food • compartment. See section 5.2 for testing of the temperature • sensor.

“Er 18”:

The fault is detected as an “open circuit” to the surface temperature sensor in the freezer compartment.

Possible faults:

Loose wires in the harness connected to (P2) on

•

the lower control board. Broken surface temperature sensor in the freezer • compartment. See section 5.2 for testing of the temperature • sensor.

note: A disconnected (P2) connector will result in an

error code 16 as this has priority.

11.3 Service mode

NEA1402

The service mode is intended as a tool to perform diagnostic troubleshooting. Before entering the “Service mode”, switch “OFF” the refrigerator with the ON/OFF button. To enter the service mode, press

and hold the “SET” button then press the ON/OFF button to the “ON” position. In this mode the refrigerator is not operating normally. Instead, a number of tests can be performed and the “SET” button is used to step through the tests. The test

number and the result of the test are displayed alternating (ashed). Stepping beyond the last test will result in a restart

from test number 1 again. The refrigerator will automatically exit the “Service mode” if no action is detected for 3 minutes. To manually exit, switch the refrigerator “OFF” and then back “ON” again.

NDA1402

no. test function test results

00 ----- ----01 LED Display panel. All LED Segments on. 02 DC Voltage check. “12” = within the proper operational range, 8.5 to 18 volts DC.

“Lo” or “hi” = outside of operational range.

03 Air temperature sensors, freezer & fresh

food.

04 Surface temperature sensors, freezer & fresh

food. 05 Door switches. “OP” = door is opened, “CL” = door is closed. 06 AC Detection. “On” = circuit is turned on, “no AC” = fault detected. 07 Turn on fresh food defrost heater. “On” = turned on, “-- --” = fault detected. 08 Turn on freezer plate defrost heater. “On” = turned on, “-- --” = fault detected. 09 Turn on drain tube/tray defrost heater. “On” = turned on, “-- --” = fault detected. 10 Turn on door frame heater. “On” = turned on. 11 Turn on fan in fresh food section. “On” = turned on, “-- --” = fault detected. 12 Turn on fan in freezer section. “On” = turned on, “-- --” = fault detected or “bl” = fan is blocked. 13 Turn on gas ignition system (NDA1402) only. “i9” = sparking, “FL” = ame is present, “-- --” = fault detected.

Degrees °F = in range, “hi” or “Lo’ = out of range, “-- --” = fault detected.

test 01: display test

All segments and dots in the displays shall now be lit.

test 02: dc Voltage test

The display shows either “Lo”, “12” or “hi” depending on the actual battery supply voltage. If the display does not show “12”, there is a severe problem with the 12 volt DC battery supply.

note: The “Lo dc” message will remain for approx 10

minutes after correct DC voltage is restored. Switching the refrigerator “OFF” and then back “ON” will clear the message immediately if DC voltage is normal.

test 03: air temperature Sensor test

The display shows the actual air temperatures in degrees Fahrenheit of the two compartments, freezer to the left and fresh food to the right. The display range is from -9° F to 41° F in the freezer and from -9° F to 59° F in the fresh food side. For temperatures below and above these ranges, the display will show “Lo” and “hi” respectively. An open circuit to a sensor will be displayed as “--”.

The out of range indications in the temperature display (“hi” and “Lo”) indicates that temperature is out of measurement circuit range. However, these indications may remain for some time after temperature is within range again. This depends on that the temperature display is

ltered with long time constants. To reset the temperature

lter memory, switch “OFF” and “ON” again. Now the tem-

perature indications will start from the actual value.

note: There is an offset between measured temperature

and shown temperature, as the indications are intended to show food temperature rather than the temperature at the sensor.

3736

test 04:

test 08:

Surface temperature Sensor test

The display shows the actual temperatures in degrees Fahrenheit on the cooling surfaces, freezer to the left and fresh food to the right. The displayable range is from -9° F to 59° F. Temperatures below or above this range will be displayed as “Lo” and “hi” respectively. An open circuit to a sensor will be displayed as “--”.

ltered with long time constants. To reset the temperature

lter memory, switch “OFF” and “ON” again. Now the tem-

perature indications will start from the actual value.

test 05: door Switch Sensor test

The display shows the actual status for the doors. “CL” stands for door closed and “OP” stands for door open. The freezer door is to the left and the fresh food door is to the right. A depressed fresh food door sensor will not darken the display in the “Service mode”.

test 06: 120 Volt ac test

If AC voltage is available, the display will show “On” and the AC relay will be activated so that the heater in the cooling unit is energized. If AC is not available, the display will show “no AC” and the relay will not be activated. A blown fuse (F5) will result in a “no AC” display. However, a faulty heater will not be detected at this test. A manual check of the heaters will be necessary to verify they are hot.

note: Replacing a blown fuse while in this test will not

clear the “no AC” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

test of the defrost Heating element in the freezer

A disconnected or broken defrosting element in the freezer results in the display “--”. A blown fuse (F4) or blown overheating protection in the element will also result in this display. Otherwise the display shows “On” and the element is energized. A fault here is also indicated with “Er 11” during normal operation.

note: Replacing a blown fuse while in this test will not

clear the “--” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

test 09: test of the defrost Heating element in the

drain tube/tray

A disconnected or broken defrosting element in the drain tube/tray results in the display “--”. A broken fuse (F6) also results in this display. Otherwise the display shows “On” and the element is energized. A fault here is also indicated with “Er 13” (or “Er 12” in case of a blown fuse) during normal operation.

note: Replacing a blown fuse while in this test will not

clear the “--” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

test 10: test of the Heating element in the door

frame and Ice-maker Waters Supply line

This test only switches on the loads. A disconnected or faulty load will not be detected. The display therefore always shows “On” here. A faulty heater will not be detected at this test. A manual check of the heaters will be necessary to verify they are hot.

test 07: test of the defrost Heating element in the

fresh food Side

A disconnected or broken defrosting element in the fresh food side results in the display “--”. A blown fuse (F6) or blown overheating protection in the element will also result in this display. Otherwise the display shows “On” and the element is energized. A fault here is also indicated with “Er 12” during normal operation.

note: Replacing a blown fuse while in this test will not

clear the “--” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

test 11: test of the fan in the fresh food Side

An open circuit to the fan in the fresh food side will result in the display “--”. Otherwise the display will show “On” and the fan is started. A fault here is also indicated with “Er 15” during normal operation.

note: Correcting this problem while in this test will not

clear the “--” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

test 12: test of the fan in the freezer

An open circuit to the fan in the freezer will result in the display “--”. A blocked fan will result in the display “bL”. Otherwise the display will show “On” and the fan is started. A fault here is also indicated with “Er 14” during normal operation.

note: Correcting this problem while in this test will not

clear the “--” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

test 13: gas operation test

In this test, gas operation may be checked. If the gas burner and the gas ignition control module are work-

ing OK, the gas ame shall be lit and the display shall

show “FL” (Flame). Before the ame is lit and spark-

ing is on, the display will show “i9” (stands for “ig” and shall be read as “ignition”). If a fault is detected “--” is shown.

note: Correcting a gas operation fault while in this test

will not clear the “--” display. Restart the “Service mode” to refresh the display message. Repeatedly press the SET button until this test is reached again.

note: For model NDE1402 (AC only) this test has no

meaning. “--” will always be displayed during this test.

When the ice maker thermostat senses the preset tem-

perature for ejection of the ice cubes, the ngers will start to rotate dumping any ice cubes and lling the mold with

water. When the storage container is full of ice, the ice level bail arm cannot return to the DOWN position. This will stop further production of ice until the container is emptied and the bail arm is returned to the down position. The absorption system will keep the compartment at the proper temperature for storage of ice. Ice making is accelerated if the thermostat is set to the coldest position. It is a good idea to do this a few hours before you anticipate

a need for ice. The rst few cycles may have small cubes due to air trapped in the water lines. The rst container of

ice cubes should be dumped if the water system has been winterized or not used for several weeks.

note: If tHe Ice maKer WaS cleaned and

draIned, no Ice cuBeS WIll Be dumPed Into tHe Storage contaIner durIng tHe fIrSt feW cycleS.

12.2 mold Heater

The mold heater uses 165 watts to thaw the ice free from the mold. It is wired in series with the thermostat which also acts as a safety device. With power to the appliance off, check for resistance between the two leads to the heater element. You should obtain a reading of approximately 80 Ohms +/- 10%. If the heater is found to be defective, replacement of the entire ice making unit is recommended for proper operation.

SectIon 12 Ice maKer

12.1 operation

The refrigerator must be allowed to pre-cool properly before starting the ice maker. The refrigerator has to be connected to 120 volts AC before the ice maker can operate. The water line manual shutoff valve (not part of Dometic unit) must be open. To start making ice, move the ice level bail arm to the DOWN position.

12.3 Ice ejector

The ice ejector blades sweep the ice from the mold cavities during the ejection cycle. The drive end of the ejector is “D” shaped for positive coupling. The bearings at both ends are lubricated with silicone grease. If the ejector blades are frozen into the ice, defrost the ice maker and manually cycle the ice making unit, making sure the ejector stops at the right location.

3938

12.4 mold thermostat

This is a single-pole, single-throw, bimetal switch. It starts an ejection cycle by closing at 15º F ± 5º F. The reset temperature is 50º F ± 5º F. The thermostat is in series with the mold heater and acts as a safety against overheating in case of a mechanical failure. If the thermostat is defective, replace it. The mold thermostat starts the ice ejection cycle. The freezer must be down to proper temperature for the mold thermostat to start the cycle.

12.5 Shut off arm

The shutoff arm is cam driven. It operates a switch to control the quantity of ice produced. During the ejection cycle the arm is raised and lowered during each of the two revolutions of the timing cam. If the shutoff arm comes to rest on top of the ice in the storage bin during either revolution, the switch will remain open and stop the ice maker at the end of that revolution. The arm has a manual shutoff built into the linkage; by raising the arm as high as possible, it will lock in that position until forced down. If the arm and switch do not operate properly, check for damage and repair or replace parts as necessary.

12.7 timing motor

This is a low-wattage, stall-type motor which is geared to the timing cam and ice ejector. It is a one RPM motor. To check the motor, disconnect power to the appliance and test for continuity between the two leads. If you have no continuity, replace the motor. If you have continuity and the motor runs, DO NOT replace.

12.6 mold Switches

The three switches are single-pole, double-throw style. They are identical and interchangeable. The holding switch assures completion of a revolution once a cycle has started. The water valve switch opens the water valve

during the ll stage of the cycle.

note: This is the only adjustable component of the ice

maker. If you use a double throw switch, do not use the N.O. terminal. The shutoff switch stops the ice maker’s operation when the storage bin is full.

12.8 Water Valve

This valve is solenoid operated. When it is open, it releases water from the source to the mold. The amount of water is proportional to the length of time the water valve switch is held closed by its timing cam. Disconnect power to the appliance, remove the wires to the water valve solenoid coil, and check for continuity between the two terminals. The Ohms value should be between 200 to 500. If you have continuity, the solenoid is good. It takes 10-15 watts to energize the solenoid coil. The mold heater and coil are in series. When the mold heater is activated, this causes the voltage to drop to about 105 VAC at the coil. The valve has a ow washer inside which acts as a pressure regulator. A strainer is installed to prevent dirt, rust, etc, from entering the valve. Check for any debris which

might obstruct the ow of water, or prevent the valve from

closing completely when the circuit is not energized. Remove any obstructions. If the valve still fails to operate properly, replace it. If the valve has been cracked from freezing this would not be a warranty item.

(SIngle)

Water ValVe

(dual)

12.10 Water fill adjustment

The correct water level in the mold is important for the proper production of ice. The size of the ice cubes depends on the amount of water which enters the mold. The cubes should be approximately 1/2” wide, 3/4” high and

2-1/2” long. If the water overows in the mold, rst check

to see if the ice maker unit is level in the appliance. Next ensure that the appliance is installed level in the RV. If

there is still water overow, adjustment of the water ll

screw is necessary. Locate the screw on the ice maker assembly. Turn the screw as necessary toward the “+” or “—” side. One full turn of the screw will make a 20 cc change in the amount of water. DO NOT turn the screw more than one full turn at a time. If the water level is too high, it can also cause the ejector blades to become frozen in the ice. Follow the procedures above to correct the problem.

W1- Blue to the door

W2- red to the Ice-maker

note: Units that have water at the door dispenser will

use a dual coil water valve. Both coils are 120 volt AC and can be tested by measuring the resistance.

W1 - Blue 400 Ohms +/- 10% W2 - Red 200 Ohms +/- 10%

12.9 Ice maker replacement

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

note: The amount of water varies, depending on water

pressure.

Adjusting screw for regulating the water supply

Clockwise to reduce Counter-clockwise to increase

12.11 fill tube

To avoid the risk of water leakage outside the inlet, make

sure the ice maker ll tube (located behind the ice maker)

is inserted far enough in the ice maker water inlet cup.

Use your ngers to verify that the ll tube is protruding approx. 1/2” into ll cup.

It may be necessary to replace the entire ice maker assembly. Disconnect the power to the appliance. Disconnect the 4 pin connector from the ice maker unit. Check each wire for continuity to make sure the wiring is good before replacing the ice maker unit. If there is no continuity on any of these wires, replace or repair them as necessary and recheck the ice maker unit to determine whether the problem was in the wiring or the unit itself. Remove the three screws holding the unit to the plate. Before replacing the ice maker assembly check the temperature of the freezer, for the unit to cycle it should be 15º F ± 5º F or cooler as the mold thermostat starts the cycle.

Should the ll tube be too short, extending the overall

length may be necessary. This can be accomplished by inserting a piece of PVC tubing (1” long x 5/8” OD) into the

end of the ll tube.

PVC tubing

4140

12.12 Water Supply

To operate properly, the water pressure in the water supply line must be greater than 15 lbs. psi. Lower water pressure, water turned off, or obstructions or air in the water line can cause low or no ice production. First check to see that the water supply is fully turned on. Visually check the

line for kinks, etc. which might obstruct the ow of water.

To remove trapped air, loosen the connection at the water solenoid valve of the appliance. Ensure that pressurized water is reaching this point, and bleed off any air in the line. Retighten the connection, making sure there are no leaks.

In some cases a foaming/overspray will be noticed around

the ll cup area. This may be noticed if the water pressure

is unregulated or in excess of 40-50 psi.

•

The insert needs to be partially (not fully) inserted into the clear tubing.

approx. 1/4”

To determine if foaming/overspray is happening:

Disconnect city water supply.

•

Turn water pump switch on.•

Set the ice maker water supply line shut-off •

valve to “full open”.

Remove the ice bin.•

Remove the cover from face of ice maker.•

Rotate the ice maker main gear/sprocket using •

channel-lock pliers until bail arm begins to lift.

Depress & hold the freezer door switch (to allow •

AC power to pass into freezer compartment &

ice maker).

Allow ice maker to cycle.•

Just before end of cycle observe water ll at rear •

of ice maker (shine ashlight into compartment

and observe cup).

Also, you can test the overspray scenario with city water supply as well by reversing steps 1 & 2 to shut off the water pump and connect to city water supply.

If foaming/spraying occurs:

1. Inspect/Replace water line insert.

Clear tube and insert need to be inserted into the •

angled ll tube so that the insert is ush with the edge of the ll tube. Spring clip needs be positioned so that it is rmly •

pinching down onto metal insert.

Incorrect

•

The larger insert (.140 ID) allows for greater ow

and greater possibility of overspray. The recom-

mended size should be (.125 ID).

.125 ID

.140 ID

correct

In most applications, removing the upper side wall vent will provide access to the ice maker ll tube. For applications using a roof vent, removal of the refrigerator may be necessary.

2. Reduce the ow of water into ice maker.

A permanent x would be to regulate the water

•

supply using a pressure reducing valve before the inlet side of our water solenoid valve (regulate between 40 and 50 psi).

A temporary solution in-the-eld would be to •

turn the manual shut-off valve “OFF”. And then reopen the valve approx 1/4 turn (less if a “ball” type valve is used).

12.13 Wiring

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

Water Valve (Single)

Refer to the wiring diagram supplied with the unit you are working on, and make sure all wiring connections are correct and tight. There are 4 wires coming from the ice maker. BlacK: Connected to incoming hot from AC power source. This could be a split wire at the AC BLACK at the circuit board or a separate power cord. WHIte: Connected to either side of the water valve and will split at the valve and hook-up to the incoming WHITE from the power source.

green/yelloW: Connected to chassis ground. BroWn: Connected to either side of water valve.

note tHe relatIVe PoSItIon of tHeSe comPonentS

In tHe folloWIng ScHematIcS

non energIzed cIrcuIt energIzed cIrcuIt

Water Valve (dual)

Refer to the wiring diagram supplied with the unit you are working on, and make sure all wiring connections are correct and tight. There are 4 wires coming from the ice maker. BlacK: Connected to incoming hot from AC power source. This could be a split wire at the AC BLACK at the circuit board or a separate power cord. WHIte: Connected to either side of the water valve (W2) and will be wired in series to water valve (W1). From the water valve it will be routed to (J1) on the interface module and split to the incoming WHITE from the power source.

green/yelloW: Connected to chassis ground. BroWn: Connected to either side of water valve

(W2)

Blue: Connected to either side of water valve (W1).

this is a freeze cycle. the mold is lled with water. The thermostat is open. all components are de-energized.

this is the start of an ejection cycle. the thermostat switches to its closed position after being suf-

ciently cooled by the ice in the

mold. the mold heater and motor are now energized. the ejector blades begin to turn.

4342

after a few degrees of motor rotation, the timing cam switches the holding switch to its normally open position; this assures completion of the cycle. the mold heater remains energized through the thermostat

circuit. During the rst half of the

cycle, the shut-off arm is raised and lowered by the timing cam and operates the shut-off switch.

Near the completion of the rst revolution, the timing cam closes the water valve switch. However since the thermostat is still closed the mold heater circuit is energized. current will not pass through the water valve solenoid and its switch. (electrical current follows the path of least resistance.)

When the ejector blades reach the ice in the mold, the motor will stall. It will remain in this position until the ice has thawed loose. during this time the mold heater remains energized.

At the end of the rst revolution

the timing cam opens the holding switch. However, since the thermostat is still closed a second revolution begins.

once again after a few degrees of rotation the timing cam closes the holding switch providing a circuit to the motor that will assure completion of this revolution. the mold heater remains energized. the shut-off arm will raise and lower again operating its switch. the ice that was ejected

during the rst revolution is dumped

into the storage bin.

near the completion of the second revolution the timing cam again closes the water valve switch. this time a circuit is completed through the water valve solenoid, its switch and mold heater. the water valve solenoid received about 105 volts. the remaining 10 volts to the mold heater are not noticeable. When the water valve solenoid is energized,

the valve opens and water rells the

mold.

Sometime during the second revolution the mold heater resets the thermostat. at this time, the mold heater is de-energized. If the storage bin is full, the shut-off arm will remain in a raised position.

the ejection cycle ends the moment that the holding switch is closed by the timing cam. the water valve switch is also opened. If the storage bin is full, as shown here, additional cy-

cles will not start until sufcient

ice is used to lower the shut-off arm, thus operating its switch.

4544

Ice maKer tyPIcal WIrIng dIagram

SectIon 13

dISPenSer lIgHt

door dISPenSer

13.1 operation

The drip tray catches small spills. The tray is removable and dishwasher safe.

It is not a drain; pour water directly into this area.

Ice dISPenSer (oPtIonal)

For a refrigerator to provide ice through the door, the ice

maker rst dumps the ice it produces into a large bin. To

DO NOT

The light can be turned on and off by pressing the “Light” touch pad. The light will illuminate the dispenser area. The light will also turn on automatically when ice or water is dispensed.

automatIc PoWer SuPPly SWItcH off

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

13.2 auger

When the paddle on the door dispenser is depressed calling for ice, a switch will be closed sending AC voltage via the yellow wire to the interface module. This contact on the interface module is a bridged set of terminals that internally send the AC voltage to the auger motor. As the auger motor rotates, this pushes the ice forward in the ice bin and down through a chute to the door dispenser. To check the motor, disconnect the 120 volt AC supply to the interface module. Measure the resistance between the wires on terminals (J6) and (J3) of the interface module. The resistance should be 4.0 Ohms +/- 10%. The resistance can also be checked directly at the motor assembly. This will require removal of the plate along the back wall of the freezer just behind the ice bin.

Water dISPenSer (oPtIonal)

The water dispenser works much like the ice dispenser. To request water at the door, simply press the lever. This will activate a switch which turns on an electric water valve

at the back of the refrigerator. Water will ow through a

separate tube right into the glass.

locK out feature

The ice dispensing system can be locked out to prevent unwanted use.

lock out•

To lock out, press the “Lock” pad for (3-5) seconds until the RED light above the Padlock comes on.

unlock•

To unlock, press the “Lock” pad for (3-5) seconds until the RED light above the Padlock goes out.

auger motor mounting plate

4.0 Ohms +/- 10%

4746

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

13.3 Solenoid

The solenoid is only activated when calling for cubed ice. When the paddle on the door dispenser is depressed calling for ice, a switch will be closed sending AC voltage via the red wire (solenoid) and yellow wire (auger) to the interface module. These contacts on the interface module are bridged separately and internally send AC voltage to the solenoid and auger motor. When the solenoid is activated, it will raise the lever in the ice bin, lifting a small door. As the auger motor rotates, this pushes the ice forward in the ice bin bypassing the crushing ngers, providing cubed ice down through a chute to the door dispenser. To check the solenoid, disconnect the 120 volt AC supply to the interface module. Measure the resistance between the wires on terminals (J8) and (J3) of the interface module. The resistance should be 33.0 Ohms +/- 10%. The resistance can also be checked directly at the solenoid assembly. This will require removal of the auger motor along the back wall of the freezer just behind the ice bin.

Ensure the ice shutter closes properly. Give the shutter a gentle push and watch to see if it closes completely. Verify for debris on the shutter that does not allow for a tight seal. If the shutter is not sealing as intended, the dispenser mechanism should be replaced.

Check Shutter

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

note: When crushed ice is called for, the solenoid will

not be activated. This forces the lever to remain down,

forcing the ice through the crushing ngers in the ice bin

and down through the chute to the dispenser. Excessive frost around the solenoid may prevent the ice

bin lever from rising. This will result in crushed ice, regardless of the request from the door controls.

33.0 Ohms +/- 10%

Excessive ice or frost will cause the solenoid to stick

13.4 Ice Shutter

The ice shutter is a door that holds back the ice into the ice bin when the dispenser is not in use. When the paddle for ice is depressed, the shutter will open allowing ice to pass through. If the interior of the coach is not air conditioned, allowing for higher temperatures and humidity, a small amount of condensation may form on the shutter area. In some cases it can develop to such a degree that it will run down the freezer door and into the living area of the coach. As the humidity is reduced, the condensation will decrease.

HEATER WIRE

There is a heater on the door that the shutter rests against. If the heater is inoperative this could allow for

condensation in the door that could run out onto the oor.

The shutter heater wires are located behind the dispenser controls. To access the heater wires remove the water drip tray at the bottom of the dispenser located on the outside of the freezer door. This will expose three screws holding the trim strip to the freezer door. Once the screws have been removed lift the trim up and pull outward at the bottom to remove the trim. Then locate and remove the three screws attaching the dispenser controls to the freezer door. This will expose the heater wires.

An Ohms test should be performed on the two clear wires going into the freezer door separate from the larger wire harness by measuring across the two pins in the connector. The resistance should be approximately 7220 Ohms +/- 10%.

13.5 Water dispenser

When the paddle on the door dispenser is depressed calling for water, a switch will be closed sending AC voltage via the blue wire to the water valve. When activated, water will be supplied to the door dispenser. If no water is dispensed, check for AC voltage at W1 (Blue) coil of the water valve assembly. If no voltage is present check the wiring harness, or the dispenser mechanism will need to be replaced. If voltage is present when the lever is depressed and no water is dispensed, verify water supply and check for leaks at the valve, water line & 90° elbow. If the above checks are OK replace the water valve assembly.

When performing these tests, if the auger, solenoid, and water dispenser work as intended, the problem is located

in the door mechanism, at cable or display panel.

note: For safety reasons, when opening the freezer

door, the ice/water dispenser and ice maker system will automatically shut off. Closing the freezer door automatically resumes operation of ice/water dispensing and ice maker operation.

13.6 door mechanism and display Panel

The control system in the door is split into two units: One unit with a power supply for the electronic control and four relays for switching on the AC to the auger motor, cube/ crushed ice solenoid, water valve and the lamp. The micro switches for sensing of the water and ice paddles are mounted separately and connected to this power supply board. The lamp and the cable from the back side are also connected to this board. The other unit is positioned just behind the front display panel and has switches that are actuated by the touch pads. The front panel also has a central processor that controls all commands to the dispenser assembly. The two units are interconnected by a

at exible cable. However, all intelligence is on the pro-

cessor board (front panel). If the unit fails to operate, rst

verify the connections of the exible cable, and then re-

place the front panel.

this is an energized circuit. Shock can occur if not tested properly. testing is to be done

by a qualied service technician.

To bypass the door controls and verify the operation of the auger, solenoid and water dispenser. Remove the drip tray and front display panel. These test can be performed at the (6) six pin connector on the left side of the dispenser assembly.

Using an insulated jumper wire, jump between 120 VAC and:

Water- Water should be dispensed. Auger- Auger should rotate. Cube- Solenoid should be activated. Fice- This connection is not used.

SectIon 14 WIrIng

14.1 Internal Wiring

Check all wires and the connectors to ensure a proper and tight connection. Also verify the refrigerator is wired per the wiring diagram for the model you are working on. (See applicable wiring diagrams for your model refrigerator). A loose connection can create erratic operation. Always check the wires at the DC terminal block, two wires in and two wires out.

14.2 external Wiring

120 Volts ac connection: The refrigerator is equipped

with a three prong (grounded) plug for protection against shock hazards and should be plugged directly into a properly grounded three prong receptacle. do not cut or remove the grounding prong from this plug.

12 Volt connection: The connection is made to the terminal block marked 12 volts DC. The control system is connected to a battery/converter circuit and could draw about 3 amps (7 amps if defrosting) at 12 volts DC. The refrigerator must be connected to the battery circuit with two wires of adequate capacity to avoid a voltage drop. Proper polarity is crucial for refrigerator operation. don’t

use the chassis for the ground circuit. no other electrical equipment or lighting should be connected to refrigerator circuit. A loose connection will create erratic

operation.

14.3 Wiring Schematics

To view typical wiring schematics look in the Lower Circuit board testing section 5, pages 19, 20 and 21. All units

should have a specic schematic on the rear of that unit.

To acquire the proper wiring schematic always have the product number when you call or e-mail.

do not use a ame to check for gas leaks.

4948

SectIon 15 mIScellaneouS

15.1 thermistor

Thermistor values at varying temperatures: See section 5.2, page 15 for procedure to test thermistors.

temperature f° temperature c° ohms

70 21 2343

65 18 2601

60 16 2917

55 13 3275

50 10 3684

45 7 4152

40 4 4687

35 2 5300

30 -1 5952

25 -4 6755

20 -7 7682

15 -9 8754

10 -12 9995

5 -15 11435 0 -18 13111

-5 -21 15064

This manual has been provided courtesy of

DARREN KOEPP - OWNER, MY RV WORKS, INC.

www.myrvworks.com

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My RV Works, Inc.

Over the years of running a mobile RV repair service, having a dedicated place to access service manuals for all the different appliances and components found on RVs was something that I always had a desire to create.

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Dometic NDA1402, NDE1402 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual