heating ISUZU TROOPER 1998 Service Repair Manual

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THIS MALUAL INCLUDES THE FOLLOWING SECTIONS:
SECTION No. CONTRNTS
00 SERVICE INFORMATION
1A HEATING AND VENTILATION
1B AIR CONDITIONING
1D COMPRESSOR OVERHAUL

SERVICE INFORMATION 00 Ð 3
TROUBLESHOOTING
CONTENTS
PAGE
Circuit Diagram.........................................................00Ð 4
Heating Cycle Troubleshooting............................................00Ð16
Fan Control Knob (Fan Switch)............................................00Ð17
Blower Motor Does Not Run............................................00Ð18
Blower Motor Does Not Run In Certain Position............................00Ð19
Blower Motor Does Not Stop at ÒOFFÓ Position............................00Ð19
Ceramic Heater.........................................................00Ð20
Ceramic Heater Does Not Operate.......................................00Ð21
Ceramic Heater Does Not Stop..........................................00Ð22
Air Conditioning Cycle Troubleshooting.....................................00Ð23
Checking Refrigerant System with Manifold Gauge.........................00Ð24
Magnetic Clutch........................................................00Ð27
6VD1/6VE1 Engine....................................................00Ð27
4JG2 Engine.........................................................00Ð31
4JX1 Engine..........................................................00Ð34
Condenser Fan..........................................................00Ð37
Condenser Fan Does Not Run...........................................00Ð38
Condenser Fan Does Not Stop..........................................00Ð39
Compressor Troubleshooting.............................................00Ð40
Individual Inspection.....................................................00Ð41

00 Ð 16 SERVICE INFORMATION
TROUBLE POSSIBLE CAUSE CORRECTION
HEATING CYCLE TROUBLESHOOTING
No heating or
Insufficient heating.·Refer to ÒFAN CONTROL KNOB (FAN
SWITCH)Ó Troubleshooting.
·Check the engine coolant temperature
after warming up the engine and check
the thermostat. Replace as necessary.
·Add engine coolant as required.
·Check if the water hose to the heater
core is clogged, collapsed or twisted.
Repair or replace as necessary.
·Check water pump function. Repair or
replace as necessary.
·Clean or replace as necessary.
·Repair the temperature control link unit
or mode doors.
·Repair or adjust the control cables.
·Repair or replace as necessary.
·Refer to ÒCERAMIC HEATERÓ
Troubleshooting.
·Repair.
·Repair.
·Repair.
·Adjust. 1. Blower motor does not run, or
runs improperly.
2. Engine coolant temperature is
low.
3. Insufficient engine coolant.
4. Circulation volume of engine
coolant is insufficient.
5. Heater core clogged or
collapsed.
6. The heater core is not provided
with air sent from the blower
motor.
7. Duct connections defective or
unsealing.
8. Ceramic heater defective.
1. Cable attaching clip is not
correct.
2. Link unit of heater unit or
blower assembly defective.
1. Link unit of heater unit or
blower assembly defective
2. Control cable is not adjusted. Control knob moves
but mode door does
not operate.
The mode door
cannot be set to the
mode selected.

00 Ð 50 SERVICE INFORMATION
Legend
1. Clutch Driver
2. Rotor Bearing Retainer
3. Pulley Rotor and Bearing
Assembly
4. Clutch Coil Assembly
5. Connector
6. Shaft Seal Parts
7. Pump Assembly
8. High Pressure Relief Valve
9. Shipping Cap
10. Special 134a Suction Port
11. Special 134a Discharge Port
Caution
The operations described below are based
on bench overhaul with the compressor
removed from the vehicle, except as noted.
They have been prepared in order of
accessibility of the components. When a
compressor is removed from the vehicle for
servicing, the amount of PAG lubricant
remaining in the compressor should be
drained, measured and recorded. This PAG
lubricant should then be discarded and an
equal amount of new PAG lubricant added to
the compressor.
The service compressor is shipped without
PAG oil. When service procedures require,
use only Isuzu approved PAG oil.
HEATING, VENTILATION AND AIR CONDITIONING(HVAC)
1
2
3
4
5
68
97
10
11
871RW002

CAUTION
When fasteners are removed, always
reinstall them at the same location from
which they were removed. If a fastener
needs to be replaced, use the correct part
number fastener for that application. If the
correct part number fastener is not available,
a fastener of equal size and strength (or
stronger) may be used. Fasteners that are not reused, and those
requiring thread locking compound, will be
called out. The correct torque values must
be used when installing fasteners that
require it. If the above conditions are not
followed, parts or system damage could
result.
HEATING AND VENTILATION 1A Ð 1
SECTION 1A
HEATING AND VENTILATION
CONTENTS
PAGE
General Description.....................................................1AÐ 2
Heater...............................................................1AÐ 2
Control Lever Assembly................................................1AÐ 3
Ventilation...........................................................1AÐ 3
Air Select Knob.......................................................1AÐ 4
Air Source Select Lever................................................1AÐ 4
Fan Control Knob.....................................................1AÐ 4
Temperature Control Knob.............................................1AÐ 4
Ceramic Heater.......................................................1AÐ 5
On-Vehicle Service......................................................1AÐ 6
Heater Unit..........................................................1AÐ 6
Heater Core and/or Mode Door..........................................1AÐ 8
Heater Mode Control Link Unit..........................................1AÐ10
Heater Temperature Control Link Unit....................................1AÐ12
Blower Assembly.....................................................1AÐ14
Blower Link Unit and/or Mode Door......................................1AÐ16
Blower Motor........................................................1AÐ18
Rear Heater Duct, Defroster Nozzle and Ventilation Duct....................1AÐ20
Center and/or Side Vent...............................................1AÐ22
Control Lever Assembly and/or Control Cables............................1AÐ24
Control Panel Illumination Bulb..........................................1AÐ27
Resistor.............................................................1AÐ28
Ceramic Heater and/or Full Hot Switch...................................1AÐ30

When the engine warming up, the warmed engine
coolant is sent out into the heater core. The heater
system supplies warm air into the passenger
compartment to warm it up.
Outside air is circulated through the heater core of
the heater unit and then back into the passenger
compartment. By controlling the mixture of outside
air and heater core air, the most comfortable
passenger compartment temperature can be
selected and maintained.
The temperature of warm air sent to the passenger
compartment is controlled by the temperature
control knob. This knob acts to open and close the
air mix door, thus controlling the amount of air
passed through the heater core.The air select knob, with its different modes, also
allows you to select and maintain the most
comfortable passenger compartment temperature.
The air source select lever is used to select either
ÒFRESHÓ for the introduction of the outside air, or
ÒCIRCÓ for the circulation of the inside air. When
the lever is set to ÒFRESHÓ, the outside air is always
taken into the passenger compartment. When
setting the lever to ÒCIRCÓ position, the circulation
of air is restricted only to the inside air with no
introduction of the outside air and the air in the
passenger compartment gets warm quickened.
However, the lever is normally set to ÒFRESHÓ to
prevent the windshield from clouding.
1A Ð 2 HEATING AND VENTILATION
GENERAL DESCRIPTION
HEATER
Side def hose
Vent box
Upper center vent duct
Lower center
vent ductBlower assembly
Control lever assembly Evaporator
assembly W/A/C
W/O A/C
Duct Heater unit
Lap vent nozzle Vent box Side def hoseDefroster nozzle
Rear heater duct
A/C - Air Conditioning This illustration is based on LHD

This illustration is based on LHD
Temperature control knob
A/C switch (W/A/C)
TEMP
A/C
Fan control knob(Fan switch) Air source select lever Air select knob
HEATING AND VENTILATION 1A Ð 3
The vehicle has cable-control-type to control by
cable the mode and temperature of the heater unit
and the mode door for the air source of the blower
assembly.The fan control is used to control the amount of air
sent out by the resistor at four levels from ÒLOWÓ
to ÒHIGHÓ.
CONTROL LEVER ASSEMBLY
VENTILATION
Set ÒAIR SOURCE SELECT LEVERÓ to ÒFRESHÓ
position and turn on the blower fan. Heating can be
done in this lever position, sending in fresh air from
outside.The blower fan also serves to deliver fresh outside
air to the vehicle interior to assure adequate
ventilation.

1A Ð 4 HEATING AND VENTILATION
AIR SELECT KNOB
The air selector knob allows you to direct heated air
into the passenger compartment through different
outlets.
1.Vent- In this position, air is discharged from
the upper air outlet. Air quantity is controlled
by the fan control knob.
2.Bi-Level- In this position, air flow is divided
between the upper air outlets and the foot air
outlets, with warmer air delivered to the floor
outlets than the air delivered to the upper air
outlets.
3.Foot- In this position, air flow is delivered to
the foot while sending approx. 30% of total
amount of air to the windshield
4.Def/Foot- In this position, air flow is delivered
to the foot, while sending approx. 40% of total
amount of air to the windshield.
5.Defrost- In this position, most of the air is
delivered to the windshield and a small
amount is delivered to the side windows.
Moving the air source select lever to the ÒCIRCÓ
position provides quickest heat delivery by closing
the blower assembly mode door. In this position,
outside air is not delivered to the passenger
compartment.
AIR SOURCE SELECT LEVER
The intake of outside air and the circulation of inside
air are controlled by sliding this lever left or right.
FAN CONTROL KNOB
This knob controls the blower motor speed to
regulate the amount of air delivered to the defrost,
foot, and ventilation ducts:
1. Low
2. Medium Low
3. Medium High
4. High
TEMPERATURE CONTROL KNOB
When the temperature control knob is in the
ÒCOLDÓ position, the air mix door closes to block
the flow of air to the heater core.
When the temperature control knob is in the
ÒHOTÓ position, the air mix door opens to allow air
to pass through the heater core and heat the
passenger compartment.
Placing the knob in an intermediate position will
cause a lesser or greater amount of air to reach the
heater core. In this mode the passenger compart-
ment temperature can be regulated.
Heater core Heater unit
TO VENT OUTLETAir mix door
VENT MODETO FOOT TO VENT OUTLET
BI-LEVEL MODE
FOOT MODE TO FOOT OUTLET
TO DEF OUTLET(LHD)
DEF/FOOT MODE TO FOOT OUTLETTO DEF OUTLETDEF MODE TO DEF OUTLET
: COLD AIR
: HOT AIR
: TEMP.CONTROLLED AIR

Full hot switch Ceramic heater Heater unit
HEATING AND VENTILATION 1A Ð 5
CERAMIC HEATER
When the fan control knob (fan switch) turns on with the temperature control knob set to ÒFULL HOTÓ (full
hot switch ÒONÓ), the ceramic heater in the heater unit gets hot, thus causing the heater blow temperature
of diesel vehicle to get high to improve the heating performance (Since the engine coolant temperature of
diesel vehicle is low, its blow temperature is also low.).
Glow plug
Full hot switch
Fan switch
Thermo switch
Less than 80¡C (177.8¡F)
CERAMIC HEATER
ÒONÓCERAMIC HEATER
ÒOFFÓ
OFF
ON
OFF
OFF
OFF
ON
ON
ON
This illustration is based on RHD

1A Ð 6 HEATING AND VENTILATION
ON-VEHICLE SERVICE
HEATER UNIT
4a
5
3
4
2
6
9
8
7
1Electro thermo connector (With A/C)
Resistor
Removal Steps
1. Instrument panel assembly
2. Water hose
3. Resistor connector
4. Duct
4a. Evaporator assembly (A/C only)
5. Instrument panel center bracket
6. Rear heater duct
7. Heater unit
8. Lap vent nozzle
9. Center ventilation lower duct
Installation Steps
To install, follow the removal steps in the
reverse order
This illustration is based on LHD