ISUZU TROOPER 1998 Service Repair Manual

1A Ð 26 HEATING AND VENTILATION
INSTALLATION
To install, follow the removal steps in the reverse order,
noting the following points:
1. Adjust the control cables
Air source control cable
1) Slide the control lever to the left (ÒCIRCÓ position).
2) Connect the control cable at the ÒCIRCÓ position of
the link unit of blower assembly and fix it with the
clip.
Temperature control cable
1) Turn the control knob to the left (ÒMAX COLDÓ
position).
2) Connect the control cable at the ÒCOLDÓ position
of the temperature control link of the heater unit
and fix it with the clip.
Air select control cable
1) Turn the control knob to the right (ÒDEFROSTÓ
position).
2) Connect the control cable at the ÒDEFROSTÓ
position of the mode control link of the heater unit
and fix it with the clip.
2. Check control cable operation.
AIR SELECTOR CABLE
Air selector knob
VENT
BI-LEVELFOOT
DEF/FOOTDEF
(DEF)
TEMPERATURE CONTROL CABLE
Temperature control knob
COLD
HOT
(MAX
COLD)
AIR SOURCE SELECT CABLE
Air source select lever (CIRC)
CIRC FRESH
Clip

HEATING AND VENTILATION 1A Ð 27
Removal Steps
1. Control lever assembly
2. Bulb socket
3. Illumination bulb
Installation Steps
To install, follow the removal steps in the
reverse order.
CONTROL PANEL ILLUMINATION BULB
2 3 1
REMOVAL
Preparation:
Disconnect the battery ground cable
1. Control Lever Assembly
Refer to ÒCONTROL LEVER ASSEMBLYÓ removal
procedure in this section.
2. Bulb Socket
Pull out the socket from the panel by turning it
counterclockwise.
3. Illumination Bulb
Pull the illumination bulb from socket.
INSTALLATION
To install, follow the removal steps in the reverse order.

1A Ð 28 HEATING AND VENTILATION
5
7
6To Blower unit
To Heater unit
34
12
Removal Steps
1. Front console assembly
2. Lower cluster assembly
3. Glove box
4. Instrument panel passenger
lower cover
5. Resistor connector
6. Duct (Heater only)
7. Resistor
Installation Steps
To install, follow the removal steps in the
reverse order.
RESISTOR
This illustration is based on RHD

HEATING AND VENTILATION 1A Ð 29
REMOVAL
Preparation:
Disconnect the battery ground cable
1. Front console assembly
2. Lower cluster assembly
3. Glove box
4. Instrument panel passenger lower cover
Refer to Section 10 ÒBODYÓ for INSTRUMENT PANEL
ASSEMBLY removal procedure.
5. Resistor connector
6. Duct (Heater only)
7. Resistor
INSTALLATION
To install, follow the removal steps in the reverse order.

1A Ð 30 HEATING AND VENTILATION
4
4a
3
Full hot switch
Cover
Clamp
22
0


25


30AUTOA
/
CO
F
FAUTOLOHI
1
y
Removal Steps
1. Instrument panel assembly
2. Instrument panel center bracket
3. Rear heater duct
4. Ceramic heater assembly
4a. Full hot switch
CERAMIC HEATER AND/OR FULL HOT SWITCH
Installation Steps
To install, follow the removal steps in
the reverse order.
This illustration is based on RHD

HEATING AND VENTILATION 1A Ð 31
REMOVAL
Preparation:
Disconnect the battery ground cable
1. Instrument panel assembly
Refer to Section 10 ÒBODYÓ for ÒINSTRUMENT
PANEL ASSEMBLYÓ removal procedure.
2. Instrument panel center bracket
Refer to Section 10 ÒCROSS BEAM ASSEMBLYÓ
removal procedure.
3. Rear heater duct
4. Ceramic heater
1) Disconnect the connector and remove the heater
fixing screw and heater harness fixing clamps.
2) Pull the ceramic heater out from heater unit.
4a. Full hot switch
Disconnect the switch connector and remove the
switch fixing screw and switch harness fixing clamp.
INSTALLATION
To install, follow the removal steps in the reverse order,
noting the following points.
1. The installation should be made with care so that
there is continuity between the switch side connector
terminals when the knob is set to the ÒFull HotÓ
position.
2. Be sure to handle the EGR and the ABS control unit
with care to avoid the disengagement of connectors.

AIR CONDITIONING 1B Ð 1
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.
SECTION 1B
AIR CONDITIONING
CONTENTS
PAGE
General Description.....................................................1BÐ 3
Air Conditioning Refrigerant Cycle Construction...........................1BÐ 3
Compressor.........................................................1BÐ 4
Magnetic Clutch......................................................1BÐ 5
Receiver/Drier.......................................................1BÐ 5
Dual Pressure Switch.................................................1BÐ 6
Triple Pressure Switch................................................1BÐ 6
Expansion Valve......................................................1BÐ 6
Evaporator..........................................................1BÐ 7
Electronic Thermostat.................................................1BÐ 7
Refrigerant Line......................................................1BÐ 7
Service Charge Valve..................................................1BÐ 7
Air Conditioning Parts.................................................1BÐ 8
On-Vehicle Service......................................................1BÐ 13
Precautions For Replacement or Repair of Air Conditioning Parts.............1BÐ 13
Compressor Assembly and Associated Parts..............................1BÐ 23
Condenser Assembly (LHD V6 without Condenser Fan).....................1BÐ 33
Condenser Fan Motor.................................................1BÐ 35
Receiver/Drier.......................................................1BÐ 37
Pressure Switch......................................................1BÐ 39
Evaporator Assembly.................................................1BÐ 42
Evaporator Core and/or Expansion Valve.................................1BÐ 44
Electronic Thermostat.................................................1BÐ 47
A/C Switch and Illumination Bulb.......................................1BÐ 48
Refrigerant Line......................................................1BÐ 49
Rear Cooler Parts.....................................................1BÐ 51

1B Ð 2 AIR CONDITIONING
Full Automatic Air Conditioning System....................................1BÐ 60
General Description.....................................................1BÐ 60
Full Automatic Air Conditioner Part Configuration.........................1BÐ 60
Circuit Diagram......................................................1BÐ 62
Function and Features.................................................1BÐ 74
Full Automatic Air Conditioner Block Diagram.............................1BÐ 75
Air Conditioning Parts.................................................1BÐ 76
Control Panel Layout..................................................1BÐ 80
Air Control Functions.................................................1BÐ 81
Operation and Function of Control Panel Switches.........................1BÐ 82
Overview of Construction, Movement and Control of Major Parts of Full Automatic
Air Conditioner System................................................1BÐ 84
Overview of Automatic Control of Full Automatic Air Conditioner............1BÐ 88
Troubleshooting........................................................1BÐ 92
Troubleshooting, Its Overview and Procedures............................1BÐ 92
Performance and Movement Checklist for Automatic Air Conditioner Related
Parts...............................................................1BÐ 95
Troubleshooting with Self-Diagnosis Function............................1BÐ 97
Inspection by Failed Location.............................................1BÐ100
Inspection of the Sensors..............................................1BÐ100
Inspection of the Intake Actuator System.................................1BÐ104
Inspection of the Mix Actuator System...................................1BÐ107
Inspection of the Mode Actuator System.................................1BÐ110
Inspection of the Fan Motor System.....................................1BÐ113
Inspection of the Magnet Clutch System.................................1BÐ118
Inspection of the Air Conditioner Room Temperature Setup System..........1BÐ123
Individual Inspection..................................................1BÐ124
On-Vehicle Service......................................................1BÐ126
Power Transistor.....................................................1BÐ126
Automatic Air Conditioner Control Unit..................................1BÐ126
In Car Sensor........................................................1BÐ127
Ambient Sensor......................................................1BÐ127
Sun Sensor..........................................................1BÐ128
Electronic Thermostat.................................................1BÐ128
Mode Actuator.......................................................1BÐ129
Mix Actuator.........................................................1BÐ129
Intake Actuator......................................................1BÐ130

AIR CONDITIONING 1B Ð 3
AIR CONDITIONING REFRIGERANT CYCLE CONSTRUCTION




 

 













 

 
 
 
 

 
 


 












 

 
 
 
 
 
 





1514
11
12
13
1610
177
34
5
2
18
96
13 Side vent
Lap ventOutside air
EngineSide vent
Cooling air
High pressure, high temperature gas
High pressure, high temperature
mixture of gas and liquid
Low pressure, low temperature
mixture of liquid and gas
Low pressure, low temperature gas High pressure, medium temperature liquidSide defrost Side defrostDefrost Center vent
GENERAL DESCRIPTION
1. Compressor
2. Magnetic clutch
3. Receiver/Drier
4. Dual pressure switch
5. Condenser
6. Evaporator assembly
7. Expansion valve
8. Temperature sensor
9. Evaporator core10. Blower motor
11. Heater unit
12. Heater core
13. Temp. control door (Air mix door)
14. Mode (DEF) control door
15. Mode (VENT) control door
16. Mode (HEAT) control door
17. Electronic thermostat

1B Ð 4 AIR CONDITIONING
The refrigeration cycle includes the following four
processes as the refrigerant changes repeatedly
from liquid to gas and back to liquid while
circulating.
EVAPORATION
The refrigerant is changed from a liquid to a gas
inside the evaporator. The refrigerant mist that
enters the evaporator vaporizes readily. The liquid
refrigerant removes the required quantity of heat
(latent heat of vaporization) from the air around the
evaporator core cooling fins and rapidly vaporizes.
Removing the heat cools the air, which is then
radiated from the fins and lowers the temperature
of the air inside the vehicle.
The refrigerant liquid sent from the expansion valve
and the vaporized refrigerant gas are both present
inside the evaporator and the liquid is converted to
gas.
With this change from liquid to gas, the pressure
inside the evaporator must be kept low enough for
vaporization to occur at a lower temperature.
Because of that, the vaporized refrigerant is sucked
into the compressor.
COMPRESSION
The refrigerant is compressed by the compressor
until it is easily liquefied at normal temperature.
The vaporized refrigerant in the evaporator is
sucked into the compressor. This action maintains
the refrigerant inside the evaporator at a low
pressure so that it can easily vaporize, even at low
temperatures close to 0¡C (32¡F).
Also, the refrigerant sucked into the compressor is
compressed inside the cylinder to increase the
pressure and temperature to values such that the
refrigerant can easily liquefy at normal ambient
temperatures.
CONDENSATION
The refrigerant inside the condenser is cooled by
the outside air and changes from gas to liquid.
The high temperature, high pressure gas coming
from the compressor is cooled and liquefied by the
condenser with outside air and accumulated in the
receiver/drier. The heat radiated to the outside air
by the high temperature, high pressure gas in the
compressor is called heat of condensation. This is
the total quantity of heat (heat of vaporization) the
refrigerant removes from the vehicle interior via the
evaporator and the work (calculated as the quantity
of heat) performed for compression.
EXPANSION
The expansion valve lowers the pressure of the
refrigerant liquid so that it can easily vaporize.
The process of lowering the pressure to encourage
vaporization before the liquefied refrigerant is sent
to the evaporator is called expansion. In addition,
the expansion valve controls the flow rate of the
refrigerant liquid while decreasing the pressure.
That is, the quantity of refrigerant liquid vaporized
inside the evaporator is determined by the quantity
of heat which must be removed at a prescribed
vaporization temperature. It is important that the
quantity of refrigerant be controlled to exactly the
right value.
COMPRESSOR
The compressor performs two main functions:
It compresses low-pressure and low-temperature
refrigerant vapor from the evaporator into high-
pressure and high-temperature refrigerant vapor to
the condenser. And it pumps refrigerant and
refrigerant oil through the A/C system.
6VD1/6VE1 engine on RHD model is equipped with
an invariable capacity five-vane rotary compressor
(DKV-14D Type).
The compressor sucks and compresses refrigerant
by the rotation of the vane installed to the shaft,
and always discharges a fixed amount of refrigerant
independent of the load of refrigerant.
The thermo sensor is installed to the front head of
the compressor to protect it by stopping its
operation when the refrigerant gas is insufficient or
when the temperature is abnormally high.
·OFF ....... 160 ±5¡C (320.0 ±41¡F)
·ON ........ 135 ±5¡C (275.0 ±41¡F)
Diesel Engine models and 6VD1/6VE1 engine on
LHD model are equipped with a swash plate type
compressor
Swash plate compressors have a swash (slanted)
plate mounted on the shaft. When the shaft turns,
the rotation of the swash plate is converted to
reciprocating piston motion which sucks in and
compresses the refrigerant gas.
Shaft seal (Lip type) is installed between the valve
plate and shaft & cylinder head to prevent
refrigerant gas leaks. A specified amount of
compressor oil is contained in the oil pan.
This oil is supplied to the cylinders, bearings, etc.,
by an oil pump which is connected to the swash
plate shaft.