Dometic 750000026TJ18FP3, 750000011TJ22F, 750000005 TJ18F User Manual

DOMETIC CORPORATION, ENVIRONMENTAL DIVISION P.O. Box 15299 I Richmond, VA 23227 USA

Phone [phone] | Fax [phone] www.dometic.com

Freightliner Refrigerator Troubleshooting Guide

For 750000005 (TJ18F) 750000011 (TJ22F)

750000026 (TJ18FP3)

Before initiating troubleshooting, the following equipment is recommended: Multimeter, 20 gauge (min) wires to use as jumpers, and 12Vdc source.

Before applying power, stand unit upright for a minimum of 1 hour to allow compressor oil to settle.

NOTE: Although, Dometic states on the packaging to always keep unit upright, we cannot control how the carrier handles our boxes. This also applies if the unit has been set on its side to affix any accessories.

If there are any questions, please contact our warranty and service department at 1-800-234- 8778 or 804-764-1313.

		Cap Tube
Load dump
including		(Expansion Device)		Condenser Coil
Power Input	Refrigerator Components

								Strainer
Danfoss				Compressor		Condenser
		Speed Resistor
Module						Cooling Fan

Freightliner Refrigerator Troubleshooting Guide

750000005 (TJ18F)

750000011 (TJ22F)

750000026 (TJ18FP3)

Locating the Dataplate

There are two Dataplates bearing the model number, serial number and technical data. One is located on the right-side panel inside the appliance (fig. 1) and the other is located on the back of the unit (fig 2).

Figure 1

Figure 2

The first three digits of the serial number indicate the Year and Week of manufacture.

Example: the Dataplate above has a serial number of 71305899

7=Year 2007

13=13th week of the year 05899=Sequential Unit Number

TROUBLE-SHOOTING

The guidelines are arranged sequentially and should be followed in order until the problem is solved. Start with “General Trouble-Shooting” sections A and B; then, go to “Specific Trouble-shooting of Electrical Components”, start with section A and work systematically to section D.

DOMETIC CORPORATION, ENVIRONMENTAL DIVISION
P.O. Box 15299 I Richmond, VA 23227 USA
Phone [phone] | Fax [phone]
www.dometic.com	Page 2 of 20

Freightliner Refrigerator Troubleshooting Guide

750000005 (TJ18F)

750000011 (TJ22F)

750000026 (TJ18FP3)

General Trouble-Shooting

A:Appliance Does Not Operate. Check:

1.The thermostat knob is “ON”, and turned, at least, half way.

2.The electrical system circuit breaker for the refrigerator is “ON”.

3.The fuse between the Danfoss Module electronic control unit and the power source is good.

4.The power supply cable is not faulty, loose or poorly connected.

5.The voltage on the Load Dump module corresponds to that of the battery. If there is a voltage drop of 0.2-0.4v check:

Positive Lead		Negative lead
from		from
Multimeter		multimeter

A.The size of the cable connecting the battery to the Load Dump module corresponds to specifications (see electrical wiring guidelines in this manual).

B.All connection points in the power circuit are properly tightened and secure.

C.There are no signs of oxidation on the battery poles or contact points and the battery is properly maintained.

6.Insure the LOAD DUMP module is installed properly on the Danfoss Module. The three pins on the LOAD DUMP module must “line up” with the top three pins of the Danfoss Module.

DOMETIC CORPORATION, ENVIRONMENTAL DIVISION
P.O. Box 15299 I Richmond, VA 23227 USA
Phone [phone] | Fax [phone]
www.dometic.com	Page 3 of 20

Freightliner Refrigerator Troubleshooting Guide

750000005 (TJ18F)

750000011 (TJ22F)

750000026 (TJ18FP3)

LOAD DUMP

Module DANFOSS

Module

7.The battery is delivering sufficient power. If the power voltage is less than 10.4VDC, the unit will not operate. Check incoming voltage with multimeter by putting the black lead on the negative terminal of the LOAD DUMP module and the red lead on the positive terminal as shown. Unit must be running to check this function.

Negative lead from multimeter

Positive Lead from Multimeter

8.If 12 volts are available to the unit as shown in step 7, check to see if the LOAD DUMP module is defective. This module is used as a surge protector for the unit. Removed the module from the unit and remove all wires. Wire the Danfoss module as shown with the wires that were on the LOAD DUMP module.

See Wiring Diagram in the later sections

	LOAD DUMP		DANFOSS
	Module		Module
DOMETIC CORPORATION, ENVIRONMENTAL DIVISION
P.O. Box 15299 I Richmond, VA 23227 USA
Phone [phone] | Fax [phone]
www.dometic.com				Page 4 of 20

Freightliner Refrigerator Troubleshooting Guide

750000005 (TJ18F)

750000011 (TJ22F)

750000026 (TJ18FP3)

The LOAD DUMP module is defective if the unit operates while wired to the DANFOSS module. Replace Load Dump module.

9.If LOAD DUMP module is working properly, check the speed resistor. This component is used to control the speed of the compressor and is located on the “T” terminal of the DANFOSS module.

Speed Resistor

Turn off power and disconnect the speed resistor from the Danfoss module. Remove the speed resistor from the blue wire and connect the blue wire on the

Danfoss module terminal “T” where the speed resistor was removed.

Connect power (12volts) back to the unit. If the unit performs, the speed resistor is faulty. Replace Speed Resistor.

10.Test the Thermostat Circuit. Remove the blue wire that is connected on terminal

“C” and remove the (black) Speed resistor (attached to the other blue wire) connected to terminal “T” of the Danfoss module. These two wires represent the thermostat circuit.

Blue Wire from thermostat

Speed Resistor connected to other blue wire from thermostat

Make sure the thermostat knob is turned on, remove the speed resistor, set multimeter to check continuity and connect meter leads to these wires as shown.

DOMETIC CORPORATION, ENVIRONMENTAL DIVISION
P.O. Box 15299 I Richmond, VA 23227 USA
Phone [phone] | Fax [phone]
www.dometic.com	Page 5 of 20

Freightliner Refrigerator Troubleshooting Guide

750000005 (TJ18F)

750000011 (TJ22F)

750000026 (TJ18FP3)

Thermostat knob

lead connections

If the thermostat is working correctly, the multimeter should indicate continuity.

In addition, check the speed resistor with the multimeter. This resistor is used to set the compressor motor speed. Connect multimeter leads to either end of resistor assembly and set meter to resistance, Ω. This is a 277-ohm resistor. It should read between 265 and 280 ohms.

11.An additional test to use if a multimeter is not available:

Turn the unit off and disconnect both blue wires that were connected to the Danfoss module terminals “T” and “C”. Place the jumper wire across these terminals as illustrated.

Energize unit and if unit operates, this action indicates the problem may be a bad thermostat. Replace thermostat.

DOMETIC CORPORATION, ENVIRONMENTAL DIVISION
P.O. Box 15299 I Richmond, VA 23227 USA
Phone [phone] | Fax [phone]
www.dometic.com	Page 6 of 20