Page 1
SERVICE MANUAL
S4307R308HPW/
MICROWAVE OVEN
R-308HK
R-308HW
MODELS
R-308HK
R-308HW
In the interest of user-safety the oven should be restored to its original
condition and only parts identical to those specified should be used.
WARNING TO SERVICE PERSONNEL: Microwave ovens contain circuitry capable of producing very high voltage and
current, contact with following parts may result in a severe,
possibly fatal, electrical shock. (High Voltage Capacitor, High
Voltage Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..)
This is a supplemental Service Manual for Models R-308HK and R-308HW. These models are quite similar to base
models R-305HK/R-305HW. Use this supplemental manual together with the Base Model Service Manual (Refer No.
is S2304R305HPW/) for complete operation, service information, etc..
TABLE OF CONTENTS
Page
PRECAUTIONS TO BE OBSERVED BEFORE AND DURING SERVICING TO
AVOID POSSIBLE EXPOSURE TO EXCESSIVE MICROWAVE ENERGY...................INSIDE FRONT COVER
BEFORE SERVICING ......................................................................................................INSIDE FRONT COVER
WARNING TO SERVICE PERSONNEL................................................................................................................1
MICROWAVE MEASUREMENT PROCEDURE ...................................................................................................2
FOREWORD AND WARNING...............................................................................................................................3
PRODUCT SPECIFICATION.................................................................................................................................4
TOUCH CONTROL PANEL..................................................................................................................................5
OVEN SCHEMATIC...............................................................................................................................................5
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE..................................................................6
SERVICE INFORMATION FOR R-305HK/R-305HW............................................................................................6
PARTS LIST ..........................................................................................................................................................7
PACKING AND ACCESSORIES ...........................................................................................................................8
SHARP CORPORATION
This document has been published to be used for after
sales service only.
The contents are subject to change without notice.
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R-308HK
R-308HW
PRECAUTIONS TO BE OBSERVED BEFORE AND
DURING SERVICING TO AVOID POSSIBLE
EXPOSURE TO EXCESSIVE MICROWAVE
ENERGY
(a) Do not operate or allow the oven to be operated with the door open.
(b) Make the following safety checks on all ovens to be serviced before activating the magnetron or other
microwave source, and make repairs as necessary: (1) interlock operation, (2) proper door closing, (3)
seal and sealing surfaces (arcing, wear, and other damage), (4) damage to or loosening of hinges and
latches, (5) evidence of dropping or abuse.
(c) Before turning on microwave power for any service test or inspection within the microwave generating
compartments, check the magnetron, wave guide or transmission line, and cavity for proper alignment,
integrity, and connections.
(d) Any defective or misadjusted components in the interlock, monitor, door seal, and microwave
generation and transmission systems shall be repaired, replaced, or adjusted by procedures described
in this manual before the oven is released to the owner.
(e) A microwave leakage check to verify compliance with the Federal Performance Standard should be
performed on each oven prior to release to the owner.
BEFORE SERVICING
Before servicing an operative unit, perform a microwave emission check as per the Microwave
Measurement Procedure outlined in this service manual.
If microwave emissions level is in excess of the specified limit, contact SHARP ELECTRONICS
CORPORATION immediately @1-800-237-4277.
If the unit operates with the door open, service person should 1) tell the user not to operate the oven
and 2) contact SHARP ELECTRONICS CORPORATION and Food and Drug Administration's
Center for Devices and Radiological Health immediately.
Service personnel should inform SHARP ELECTRONICS CORPORATION of any certified unit found
with emissions in excess of 4mW/cm2. The owner of the unit should be instructed not to use the unit
until the oven has been brought into compliance.
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Page 3
WARNING TO SERVICE PERSONNEL
Microwave ovens contain circuitry capable of producing very high voltage and current, contact with
following parts
fatal, electrical shock.
(Example)
High Voltage Capacitor, High Voltage Power Trans-
former, Magnetron, High Voltage Rectifier Assembly, High Voltage Harness etc..
Read the Service Manual carefully and follow all
instructions.
may result in a severe, possibly
Don't Touch !
Danger High Voltage
R-308HK
R-308HW
Before Servicing
1. Disconnect the power supply cord , and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
WARNING:RISK OF ELECTRIC SHOCK.
DISCHARGE THE HIGH-VOLTAGE
CAPACITOR BEFORE SERVICING.
The high-voltage capacitor remains charged about 60
seconds after the oven has been switched off. Wait for 60
seconds and then short-circuit the connection of the highvoltage capacitor (that is the connecting lead of the highvoltage rectifier) against the chassis with the use of an
insulated screwdriver.
Whenever troubleshooting is performed the power supply
must be disconnected. It may, in some cases, be necessary
to connect the power supply after the outer case has been
removed, in this event,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect the leads to the primary of the power
transformer.
5. Ensure that the leads remain isolated from other
components and oven chassis by using insulation tape.
6. After that procedure, reconnect the power supply cord.
When the testing is completed,
1. Disconnect the power supply cord, and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Reconnect the leads to the primary of the power
transformer.
5. Reinstall the outer case (cabinet).
6. Reconnect the power supply cord after the outer case is
installed.
7. Run the oven and check all functions.
After repairing
1. Reconnect all leads removed from components during
testing.
2. Reinstall the outer case (cabinet).
3. Reconnect the power supply cord after the outer case is
installed.
4. Run the oven and check all functions.
Microwave ovens should not be run empty. To test for the
presence of microwave energy within a cavity, place a cup
of cold water on the oven turntable, close the door and set
the power to HIGH and set the microwave timer for two (2)
minutes. When the two minutes has elapsed (timer at zero)
carefully check that the water is now hot. If the water
remains cold carry out Before Servicing procedure and reexamine the connections to the component being tested.
When all service work is completed and the oven is fully
assembled, the microwave power output should be checked
and a microwave leakage test should be carried out.
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R-308HK
R-308HW
MICROWAVE MEASUREMENT PROCEDURE
A. Requirements:
1) Microwave leakage limit (Power density limit): The power density of microwave radiation emitted by a microwave oven
should not exceed 1mW/cm2 at any point 5cm or more from the external surface of the oven, measured prior to acquisition
by a purchaser, and thereafter (through the useful life of the oven), 5 mW/cm2 at any point 5cm or more from the external
surface of the oven.
2) Safety interlock switches:
Primary interlock relay and door sensing switch shall prevent microwave radiation emission in excess of the requirement
as above mentioned, secondary interlock switch shall prevent microwave radiation emission in excess of 5 mW/cm
any point 5cm or more from the external surface of the oven.
B. Preparation for testing:
Before beginning the actual measurement of leakage, proceed as follows:
1) Make sure that the actual instrument is operating normally as specified in its instruction booklet.
Important:
Survey instruments that comply with the requirement for instrumentation as prescribed by the performance standard for
microwave ovens, 21 CFR 1030.10(c)(3)(i), must be used for testing.
2) Place the oven tray in the oven cavity.
3) Place the load of 275±15 ml (9.8 oz) of tap water initially at 20±5˚C (68˚F) in the center of the oven cavity.
The water container shall be a low form of 600 ml (20 oz) beaker with an inside diameter of approx. 8.5 cm (3-1/2 in.)
and made of an electrically nonconductive material such as glass or plastic.
The placing of this standard load in the oven is important not only to protect the oven, but also to insure that any leakage
is measured accurately.
4) Set the cooking control on Full Power Cooking Mode.
5) Close the door and select a cook cycle of several minutes. If the water begins to boil before the survey is completed,
replace it with 275 ml of cool water.
2
at
C. Leakage test:
Closed-door leakage test (microwave measurement)
1) Grasp the probe of the survey instrument and hold it perpendicular to the gap between the door and the body of the oven.
2) Move the probe slowly, not faster than 1 in./sec. (2.5 cm/sec.) along the gap, watching for the maximum indication on
the meter.
3) Check for leakage at the door screen, sheet metal seams and other accessible positions where the continuity of the metal
has been breached (eg., around the switches, indicator, and vents).
While testing for leakage around the door pull the door away from the front of the oven as far as is permitted by the closed
latch assembly.
4) Measure carefully at the point of highest leakage and make sure that the highest leakage is no greater than 4mW/cm2,
and that the secondary interlock switch and the primary interlock relay do turn the oven OFF before any door movement.
NOTE: After servicing, record data on service invoice and microwave leakage report.
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R-308HK
R-308HW
SERVICE MANUAL
MICROWAVE OVEN
R-308HK/ R-308HW
FOREWORD
This Manual has been prepared to provide Sharp Electronics Corp. Service Personnel with Operation and Service
Information for the SHARP MICROWAVE OVENS, R-308HK and R-308HW.
The models R-308HK and R-308HW are quite similar to base models R-305HK/R-305HW (Refer No. is S2304R305HPW/).
It is recommended that service personnel carefully study the entire text of this manual and the base model's manual so that
they will be qualified to render satisfactory customer service.
Check the interlock switches and the door seal carefully. Special attention should be given to avoid electrical shock and
microwave radiation hazard.
WARNING
Never operate the oven until the following points are ensured.
(A) The door is tightly closed.
(B) The door brackets and hinges are not defective.
(C) The door packing is not damaged.
(D) The door is not deformed or warped.
(E) There is no other visible damage with the oven.
Servicing and repair work must be carried out only by trained service personnel.
DANGER
Certain initial parts are intentionally not grounded and present a risk of electrical shock only during servicing.
Service personnel - Do not contact the following parts while the appliance is energized;
High Voltage Capacitor, Power Transformer, Magnetron, High Voltage Rectifier Assembly, High Voltage
Harness;
If provided, Vent Hood, Fan assembly, Cooling Fan Motor.
All the parts marked “*” on parts list are used at voltages more than 250V.
Removal of the outer wrap gives access to voltage above 250V.
All the parts marked “∆” on parts list may cause undue microwave exposure, by themselves, or when they are damaged,
loosened or removed.
SHARP ELECTRONICS CORPORATION
SHARP PLAZA, MAHWAH,
NEW JERSEY 07430-2135
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R-308HK
R-308HW
SPECIFICATION
ITEM DESCRIPTION
Power Requirements 120 Volts / 13.5 Amperes
60 Hertz
Single phase, 3 wire grounded
Power Output 1100 watts (IEC TEST PROCEDURE)
Operating frequency of 2450MHz
Case Dimensions Width 20-1/2"
Height 12-1/4"
Depth 17-3/4"
Cooking Cavity Dimensions Width 14-1/2"
Height 8-1/8"
1.0 Cubic Feet Depth 15-1/4"
Control Complement Touch Control System
Clock ( 1:00 - 12:59 )
Timer (0 - 99 min. 99 seconds)
Microwave Power for Variable Cooking
Repetition Rate;
P-HI..................................................Full power throughout the cooking time
P-90 ....................................................................approx. 90% of Full Power
P-80 ....................................................................approx. 80% of Full Power
P-70 ....................................................................approx. 70% of Full Power
P-60 ....................................................................approx. 60% of Full Power
P-50 ....................................................................approx. 50% of Full Power
P-40 ....................................................................approx. 40% of Full Power
P-30 ....................................................................approx. 30% of Full Power
P-20 ....................................................................approx. 20% of Full Power
P-10 ....................................................................approx. 10% of Full Power
P-0 ....................................................No power throughout the cooking time
POPCORN pad, MINUTE PLUS pad
REHEAT pad, COOK pad
DEFROST pad, Number selection pads
POWER LEVEL pad, TIMER/CLOCK pad
STOP/CLEAR pad, START pad
Oven Cavity Light Yes
Safety Standard UL Listed FCC Authorized
DHHS Rules, CFR, Title 21, Chapter 1, Subchapter J
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Page 7
TOUCH CONTROL PANEL
R-308HK
R-308HW
NOTE:
Some one-touch cooking features such as "MINUTE PLUS" are disabled after three minutes when the oven is not in use. These features
are automatically enabled when the door is opened and closed or the
STOP/ CLEAR pad is pressed.
120V AC
60 Hz
SCHEMATIC
GRN
N.O.
C/T FUSE TEMPERATURE
FUSE 150˚C (OVEN)
OL
OVEN LAMP
RELAY
(RY1)
COM.
SECONDARY
INTERLOCK
SWITCH
CONTROL UNIT
OVEN
LAMP
TTM
TURNTABLE
MOTOR
FM
FAN
MOTOR
N.O.
COM.
B2
PRIMARY
INTERLOCK
RELAY
(RY2)
DOOR
SENSING
SWITCH
POWER
TRANSFORMER
B1
MONITOR
SWITCH
NOTE: CONDITION OF OVEN
1. DOOR CLOSED
2. CLOCK APPEARS ON DISPLAY NOTE: " " indicates components with potential above 250V.
CAPACITOR
0.94µF
AC 2200V
RECTIFIER
MAGNETRON
Figure O-1. Oven Schematic-Off Condition
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R-308HK
R-308HW
COMPONENT REPLACEMENT AND ADJUSTMENT PROCEDURE
MAGNETRON REMOVAL
Removal
1. Disconnect the power supply cord and then remove
outer case.
2. Open the door and block it open.
3. Discharge high voltage capacitor.
4. Disconnect all wire leads from magnetron.
5. Remove the one (1) screw holding the chassis support
to the magnetron.
6. Release the chassis support from the hole of the oven
cavity front flange.
7. Remove the two (2) screws holding air duct to magnetron
and oven cavity top plate.
8. Remove the air duct from oven.
9. Carefully remove the four (4) screws holding magnetron
to waveguide flange.
10.Remove magnetron with care so that magnetron antenna
is not hit by any metal object around antenna.
11.Now, the magnetron is free.
Reinstallation
1. Reinstall the magnetron to waveguide flange with the
four (4) screws.
2. Reinstall the air duct to the oven cavity top plate and the
magnetron with two (2) screws.
3. Insert the end of the chassis support into the hole of the
oven cavity front flange.
4. Hold the other end of the chassis support to the magnetron
with the one (1) screw.
5. Reconnect the wire leads to the magnetron. Refer to
"PICTORIAL DIAGRAM".
6. Reinstall outer case and check that the oven is operating
properly.
CAUTION: WHEN REPLACING MAGNETRON, BE SURE
THE R.F. GASKET IS IN PLACE AND MOUNTING SCREWS ARE TIGHTENED SECURELY.
SERVICE INFORMATION FOR BASE MODELS R-305HK AND R-305HW
The following parts have been added the base models R-305HK and R-305HW from February 2003 production.
REF. NO. PART NO. DESCRIPTION Q'TY CODE
4-16 MROD-A019WREZ Chassis support 1
4-17 PCUSGA616WRPZ Cushion 1
7-12 XHTSD40P08000 Screw : 4mm x 8mm 1
In accordance with above addtional parts, procedure of "MAGNETRON REMOVAL" should be refer to above
procedure.
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Page 9
PARTS LIST
Note: The parts marked “∆” may cause undue microwave exposure.
The parts marked “*” are used in voltage more than 250V.
REF. NO. PART NO. DESCRIPTION Q'TY CODE
ELECTRIC PARTS
1-1 QSW-MA147WRZZ Secondary interlock switch / door sensing switch 2 AG
1-2 FFS-BA034WRKZ
1-3 FACCDA083WRE0 Power supply cord 1 AQ
1-3 FACCDA085WREZ Power supply cord (Interchangeable) 1 AQ
1-4 FH-DZA075WRK0 High voltage rectifier assembly 1 AR
*
1-4 FH-DZA109WRKZ High voltage rectifier assembly(Interchangeable) 1 AR
*
1-5 RC-QZA213WRE0 High voltage capacitor 1 AV
*
1-5 RC-QZA286WRZZ High voltage capacitor (Interchangeable) 1 AV
*
1-5 RC-QZA211WRE0 High voltage capacitor (Interchangeable) 1 AV
*
1-6 RMOTEA346WRE0 Fan motor 1 AV
1-6 RMOTEA356WRE0 Fan motor (Interchangeable) for production use 1 -1-7 QFS-TA014WRE0 Temperature fuse 150deg.C (oven) 1 AG
1-8 RLMPTA082WRZZ Oven lamp 1 AL
1-8 RLMPTA085WRZZ Oven lamp (Interchangeable) for production use 1 -1-9 RMOTDA211WRE0 Turntable motor 1 AS
1-9 RMOTDA186WRE0 Turntable motor (Interchangeable) 1 AW
1-10 RTRN-A705WRZZ Power transformer 1 BK
*
∆
1-11 RV-MZA288WRE0 Magnetron 1 BK
*
∆
1-11 RV-MZA321WRZZ Magnetron (Interchangeable) for production use 1 --
*
2-1 GCABUA883WRPZ Outer case cabinet (R-308HW) 1 BF
2-1 GCABUA889WRPZ Outer case cabinet (R-308HK) 1 BF
2-2 FDAI-A265WRYZ Bottom plate 1 AW
2-3 GLEGPA074WRE0 Foot 4 AC
3-1 CPWBFA858WRKZ Control unit assembly 1 BQ
3-2 HPNLCB804WRFZ Control panel frame (R-308HW) 1 AS
3-2 HPNLCB805WRFZ Control panel frame (R-308HK) 1 AS
3-3 PSHEPA913WRZZ Graphic sheet (R-308HW) 1 AW
3-3 PSHEPA924WRZZ Graphic sheet (R-308HK) 1 AW
3-4 XOTSD40P08000 Screw : 4mm x 8mm 2 AA
3-5 JBTN-B241WRFZ Open button (R-308HW) 1 AG
3-5 JBTN-B242WRFZ Open button (R-308HK) 1 AG
3-6 MSPRCA050WRE0 Button spring 1 AB
4-1 PHOK-A131WRFZ Latch hook 1 AL
∆
4-2 LBNDKA163WRPZ Capacitor holder 1 AK
4-3 NFANJA020WRE0 Fan blade 1 AG
4-4 ************* Oven cavity (Not a replacement part) 1--
∆
4-5 MLEVPA233WRF0 Switch lever 1 AG
4-6 PCLICA032WRE0 Hand clip 4 1 AD
4-7 PCOVPA394WREZ Waveguide cover 1 AK
4-8 PDUC-A833WRPZ Air duct 1 AM
4-9 PDUC-A832WRWZ Fan duct 1 AP
4-10 PPACGA176WREZ TTM packing 1 AC
4-11 PCUSGA399WRE0 Cushion 1 AF
4-12 PCUSUA278WRP0 Cushion 1 AB
4-13 PCUSUA235WRP0 Cushion 1 AE
4-14 PCUSGA614WRPZ Cushion 1 AE
4-15 PCUSGA615WRPZ Cushion 1 AE
4-16 MROD-A019WREZ Chassis support 1 AN
4-17 PCUSGA616WRPZ Cushion 1 AK
5-1 FDORFA364WRTZ Door panel 1 AS
∆
5-2 PSHEPA382WRE0 Sealer film 1 AH
5-3 GWAKPA897WRFZ Door frame (R-308HW) 1 AX
∆
5-3 GWAKPA898WRFZ Door frame (R-308HK) 1 AX
∆
5-4 HPNL-A801WRRZ Door screen (R-308HW) 1 AU
5-4 HPNL-A803WRRZ Dooe screen (R-308HK) 1 AU
5-5 LSTPPA188WRF0 Latch head 1 AG
∆
5-6 MSPRTA187WRE0 Spring 1 AC
5-7 GCOVHA450WRFZ Choke cover 1 AG
C/T fuse(150deg.C/20A) and monitor switch (D3V-1G-2C25) assembly
1AS
CABINET PARTS
CONTROL PANEL PARTS
OVEN PARTS
DOOR PARTS
R-308HK
R-308HW
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R-308HK
R-308HW
REF. NO. PART NO. DESCRIPTION Q'TY CODE
MISCELLANEOUS
6-1 FROLPA101WRKZ Turntable support 1 AR
6-2 NTNT-A117WREZ Turntable 1 AS
6-3 FW-VZB968WREZ Main wire harness 1 AT
6-4 TCAUAA268WRRZ DHHS caution label 1 AF
6-5 TCAUAA280WRRZ Monitor caution 1 AF
6-6 TINSEA973WRRZ Instruction book 1 AP
SCREWS,NUTS AND WASHERS
7-1 XHPSD40P08K00 Screw : 4mm x 8mm 2 AA
7-2 LX-CZA070WRE0 Special screw 2 AC
7-3 LX-CZA073WRE0 Special screw 2 AC
7-4 LX-CZ0052WRE0 Special screw 2 AA
7-5 LX-EZA042WRE0 Special screw 2 AB
7-6 XHPSD30P06000 Screw : 3mm x 6mm 1 AA
7-7 XHPSD40P08000 Screw : 4mm x 8mm 5 AA
7-8 XHTSD40P08RV0 Screw : 4mm x 8mm 4 AA
7-9 XHTSD40P12RV0 Screw : 4mm x 12mm 1 AA
7-10 XOTSD40P08000 Screw : 4mm x 8mm 14 AA
7-11 XOTSE40P08000 Screw : 4mm x 8mm (R-308HW) 1 AA
7-11 XOTSF40P08000 Screw : 4mm x 8mm (R-308HK) 1 AA
7-12 XHTSD40P08000 Screw : 4mm x 8mm 1
HOW TO ORDER REPLACEMENT PARTS
To have your order filled promptly and correctly, please furnish the following information.
1. MODEL NUMBER 2. REF. NO. 3. PART NO. 4. DESCRIPTION
Order Parts from the authorized SHARP parts Distributor for your area.
Defective parts requiring return should be returned as indicated in the Service Policy.
PACKING AND ACCESSORIES
FOAM SHEET
SPAKHA012WREZ
(only for R-308HK)
DOOR PROTECTION SHEET
SPADPA204WRE0
6-6 INSTRUCTION BOOK
6-2 TURNTABLE TRAY
TOP PAD ASSEMBLY
FPADBA515WRKZ
PLASTIC SHEET (for R-308HK)
SPADPA616WREZ
PLASTIC BAG
SSAKHA034WRE0
CABINET COVER
SPAKHA011WRE0
(only for R-308HK)
BOTTOM PAD ASSEMBLY
FPADBA517WRKZ
INTO THE
OVEN CAVITY
TRAY PAD ASSY
(CPADBA317WRKZ)
6-1 TURNRTABLE SUPPORT
PACKING CASE
FPAK-A467WRKZ [R-308HW]
FPAK-A474WRKZ [R-308HK]
Not replaceable items.
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R-308HK
R-308HW
1
OVEN AND CABINET PARTS
A
B
C
4-13
D
4-6
4-4
1-7
2
3
45
6
7-10
7-2
A
7-10
7-10
2-1
B
4-9
A
7-2
4-15
7-11
4-3
7-6
1-2
1-6
7-8
4-16
7-9
1-3
7-12
C
6-4
7-3
6-5
7-10
7-3
A
7-10
D
1-8
7-7
7-10
7-8
4-8
1-11
E
4-7
6-2
7-4
4-10
F
1-9
1-10
4-12
7-5
4-14
4-17
4-1
4-5
7-7
1-1
E
F
1-2
2-2
7-1
4-11
7-8
1-1
4-2
6-1
7-1
1-5
G
1-4
G
2-3
7-10
H
2-3
2-3
2-3
7-10
7-10
H
7-10
1
2
3
45
6
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Page 12
R-308HK
R-308HW
1
2
3
45
6
3-4
A
CONTROL PANEL PARTS
3-2
A
3-1
B
B
3-4
DOOR PARTS
C
3-6
5-7
3-5
C
3-3
D
5-2
D
5-1
5-3
E
E
5-4
F
F
5-6
5-5
MISCELLANEOUS
G
G
6-3
H
1
2
3
Actual wire harness may be different from illustration.
45
2003 SHARP CORP. (2S1.700E) Printed in U.S.A
6
H
10
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