service ISUZU TROOPER 1998 Service Owner's Guide

SERVICE INFORMATION 00 Ð 15
D08RY00135
ECM
(J2-11)
0.5 L/P
I-25
I-25
3
I-25 2
I-25 6
I-25
5
4
1H-166
0.3R/G0.85G/R 0.85G/R
ILLUMINATION
CONTROLLER TAIL RELAY(4)
ENGINE
WARMING
SW
1.25B 0.5B
C-74C-741 2THERMO SWH-2417
0.5G/W 0.5G/W
0.5 L/P
0.5G/B
H-2516
H-4216
H-52
0.5B
H-1615

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.

SERVICE INFORMATION 00 Ð 17
FAN CONTROL KNOB (FAN SWITCH)
Current flows to the blower motor through the
Heater & A/C relay (B-36) to activate the rotation of
the blower motor by turning ÒONÓ the fan controlknob (fan switch). Blower motor speed is controlled
in stages by the resistor, by operating the switch
from ÒLOWÓ to ÒHIGH.Ó
12
34
B-36B-1B-2
1234561
2123
45 6
I-41B-5I-18
1
2
B-36RELAY;
HEATER & ACC-19
25A
BLOWER
2
3
6
4
1
6
3
5
2
1
MBLOWER
MOTOR2
1
RHD
OFF
B-5B-5
I-18
BLOWER
RESISTOR FAN SW.
I-41
B-1
B-2(LHD) BODY-RH (RHD) BODY-LH
D08RY00167

00 Ð 18 SERVICE INFORMATION
BLOWER MOTOR DOES NOT RUN
·IS NO. C-19 (25A) FUSE OK?
·IS BLOWER RELAY (B-36) OK?
YESNO
REPLACE
NO
REPLACE
NO
REPLACE
NO
REPLACE CONTROL LEVER ASSEMBLY
NO
REPLACE
NO
OPEN CIRCUIT BETWEEN NO. C-19
(25A) FUSE AND NO. B5-1 (NO. B5-2;
RHD)
YES
·IS RESISTOR OK?
YES
·IS FAN CONTROL KNOB (FAN SWITCH) OK?
YES
·IS BLOWER MOTOR OK?
YES
·TURN THE IGNITION SWITCH ÒONÓ (ENGINE IS
RUNNING)
·FAN CONTROL KNOB (FAN SWITCH) ÒONÓ
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT
AT CHASSIS SIDE CONNECTOR TERMINAL NO. B5-1
(NO. B5-2; RHD)
YES
POOR GROUND OR OPEN CIRCUIT EITHER BETWEEN
CHASSIS SIDE CONNECTOR TERMINAL NO. B5-2
(NO. B5-1; RHD) AND NO. I-41-2 OR NO. I18-1 AND BODY
GROUND NO. B-2 (NO. B-1; RHD)

SERVICE INFORMATION 00 Ð 19
BLOWER MOTOR DOES NOT RUN IN CERTAIN
POSITION
A1 : (LOW)
BLOWER MOTOR DOES
B2 : (MEDIUM LOW)
NOT RUN AT
C3 : (MEDIUM HI) POSITION
D4 : (HIGH)
* CHECKING IS PERFORMED ONLY WHEN IN
THE MALFUNCTION MODE.
·IS RESISTOR OK?
YES
·IS FAN CONTROL KNOB (FAN SWITCH) OK?
YES
ACONDITION:
·OPEN CIRCUIT BETWEEN CHASSIS SIDE CONNECTOR
TERMINAL NO. I41-1 AND NO. I18-2
BCONDITION:
·OPEN CIRCUIT BETWEEN CHASSIS SIDE CONNECTOR
TERMINAL NO. I41-4 AND NO. I18-5
CCONDITION:
·OPEN CIRCUIT BETWEEN CHASSIS SIDE CONNECTOR
TERMINAL NO. I41-6 AND NO. I18-3
DCONDITION:
·OPEN CIRCUIT BETWEEN CHASSIS SIDE CONNECTOR
TERMINAL NO. I41-3 AND NO. I18-6
NO
REPLACE
NO
REPLACE CONTROL LEVER
ASSEMBLY
BLOWER MOTOR DOES NOT STOP AT ÒOFFÓ
POSITION
·IS FAN CONTROL KNOB (FAN SWITCH) OK?
YES
SHORT CIRCUIT BETWEEN CHASSIS SIDE
CONNECTOR TERMINAL
·NO. B5-2 (NO. B5-1 : RHD) AND NO. I41-2
(OR)
·NO. I41-3 AND NO. I18-6
(OR)
·NO. I41-6 AND NO. I18-3
(OR)
·NO. I41-4 AND NO. I18-5
(OR)
·NO. I41-1 AND NO. I18-2
NO
REPLACE CONTROL LEVER
ASSEMBLY

00 Ð 20 SERVICE INFORMATION
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 turns on and the blow temperature
goes up. When the ceramic heater turns on, FICDstarts to operate at the same time. When either one
of the fan switch, the full hot switch or the thermo
switch (which turns on when the coolant tempera-
ture gets below 80°C (176°F) turns off, the ceramic
heater also turns off.
FL-3
40A
C/HEATER
RELAY;
HEATER A/CECM
(J1-23)
24
13
C-20
10A
A/C
FL-1
80A
MAIN
B-18B-1
B-36
1
3
X-12
2
4
1
3
X-21
2
4
1
2
1
2
4
13
24
1
1
2CERAMIC
HEATER
FAN SW.
B-19
B-48
I-18
B-44
B-49
RELAY;
THERMO
SW
RELAY;
CERAMIC
HEATER
DIODE
FULL HOT
SW.
B-1
B-48
1
21
22112
B-49
I-18
213
5 4612
34
B-36X-12X-21
1234
B-44
(RHD)
B-2(LHD)
B-2
D08RWD66

SERVICE INFORMATION 00 Ð 21
CERAMIC HEATER DOES NOT OPERATE
·ARE NO. FL-3 (40A) AND NO. C-20 (10A) OK?
YESNO
REPLACE
REPLACE
REPLACE
REPLACE
·ARE A/C AND CERAMIC HEATER RELAYS OK?
YESNO
·ARE BLOWER MOTOR AND FAN SW. OK?
YESNO
·IS FULL HOT SW. OK?
·DOES TEMP. CONTROL LINK (HEATER UNIT)
OPERATE CORRECTLY?
YESNO
REPLACE·TURN THE IGNITION SW. ÒONÓ (ENGINE IS RUNNING)·CERAMIC HEATER ÒONÓ
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. B48-1
YESNO
OPEN CIRCUIT·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. B48-2
YESNO
CERAMIC HEATER DEFECTIVE·CHECK THE CERAMIC HEATER OR CERAMIC HEATER-
RELATED HARNESS FOR A POOR GROUND AND REPAIR
IT AS NECESSARY
YESNO
·DOES CONTROL LEVER CABLE OPERATE CORRECTLY?·IS THERMO RELAY OK?
YESNO
NOYES
ADJUST OR REPLACEREPAIR OR REPLACE
TEMP. CONTROL UNIT

00 Ð 22 SERVICE INFORMATION
CERAMIC HEATER DOES NOT STOP
WHEN THE IGNITION SW. ÒOFFÓ, DOES CERAMIC HEATER
STOP?
YESNO
CERAMIC HEATER RELAY DEFECTIVE·SHORT CIRCUIT BETWEEN CHASSIS SIDE RELAY TERMINAL
NO. X12-3 AND CHASSIS SIDE CONNECTOR TERMINALNO. B49-1

SERVICE INFORMATION 00 Ð 23
AIR CONDITIONING CYCLE TROUBLESHOOTING
No cooling or insuffi-
cient cooling
Insufficient velocity
of cooling air1. Magnetic clutch does not run
2. Compressor is not rotating properly
·Drive belt loosened or broken
·Magnetic clutch face is not
clean and slips
·Incorrect clearance between
magnetic drive plate and pulley
·Compressor oil leaks from shaft
seal or shell
·Compressor seized
3. Insufficient or excessive charge of
refrigerant
4. Leaks in the refrigerant system
5. Condenser clogged or insufficient
radiation
6. Temperature control link unit of the
heater unit defective
7. Unsteady operation due to foreign
substance in expansion valve
8. Poor operation of electronic thermo-
stat
1. Evaporator clogged or frosted
2. Air leaking from cooling unit or air
duct
3. Blower motor does not rotate prop-
erly·Refer to ÒMAGNETIC CLUTCHÓ
troubleshooting
·Adjust the drive belt to the specified
tension or replace the drive belt
·Clean the magnetic clutch face or
replace
·Adjust the clearance (Refer to
Section 1D ÒCOMPRESSOR OVER-
HAULÓ
·Replace the compressor
·Replace the compressor
·Discharge and recover refrigerant.
Recharge to specified amount.
·Check refrigerant system for leaks
and repair as necessary
Discharge and recover refrigerant.
Recharge to specified amount.
·Clean the condenser or replace as
necessary
·Check radiator or condenser fan
function
·Repair the link unit
·Replace the expansion valve
·Check electronic thermostat and
replace as necessary
·Check evaporator core and replace
or clean the core
·Check evaporator and duct connec-
tion, then repair as necessary
·Refer to Section 00 for ÒFAN
CONTROL KNOB (FAN SWITCH)Ó
troubleshooting
* For the execution of the charging and discharging operation in the table above, refer to the ÒRECOVERY,
RECYCLING, EVACUATING AND CHARGINGÓ in section 1B.
TROUBLEPOSSIBLE CAUSECORRECTION

00 Ð 24 SERVICE INFORMATION
CHECKING REFRIGERANT SYSTEM
WITH MANIFOLD GAUGE
Conditions;
·Ambient temperature at approx. 25 ~30°C (77
~86°F)
·Run the engine at Idling
·A/C switch is ÒONÓ
·Run the blower motor at Ò4Ó (high) position
·Temperature control knob sets at ÒMAX COLDÓ
·Air source selector lever at ÒCIRCÓ
·Close the all doors
Normal pressures kpa (kgácm
2/ PSI);
Low-pressure side:
Approx. 147 Ð 294 (1.5 Ð 3.0 / 21 Ð 43)
High-pressure side:
Approx. 1373 Ð 1863 (14 Ð 19 / 199 Ð 270 )
Connect the manifold gauge
Low-pressure hose (LOW)~Suction side
High-pressure hose (HI)~Discharge side (Low side) (High side)