engine ISUZU TROOPER 1998 Service Owner's Manual

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 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 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 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)

SERVICE INFORMATION 00 Ð 27
MAGNETIC CLUTCH
When the A/C switch and the fan control knob (fan
switch) are turned on with the engine running,
current flows through the thermostat and the com-
pressor relay to activate the magnetic clutch.
The air conditioning can be stopped by turning off
the A/C switch or the fan control knob (fan switch).
However, even when the air conditioning is in oper-ation, the electronic thermostat, the pressure switch
or the PCM (6VD1/6VE1 Engine) is used to stop the
air conditioning temporarily by turning off the mag-
netic clutch in the prearranged conditions to reduce
the engine load which is being caused by the rise in
the engine coolant temperature, and the accelera-
tion of the vehicle, etc.
123
45 6
RELAY; A/C
B-36C-20
10A
A/C FL-1
80A
MAIN
1
2
B-2
C-25
2
4
X-5
1
3 (3)
(1)
4
13
24
1
A/C SW.
FAN SW.
I-23
PRESSURE
SW.
RELAY;
THERMOSTAT
B-2
X-7 C-25
C-1C-3E-3I-23
BATTERY
X-7
RELAY: A/C
COMPRESSOR
1
E-3
MAGNETIC
CLUTCHMg
OFF
I-18
2
6
1
321123
12
3412
11
213
5 46
I-18
X-5
B-1(LHD) (RHD)
B-1
1
2 34
W/ CONDENSER
FAN
2
4
1
3
C-3PCM (E15)
C-1PCM (B14)
3
1
2
ELECTRONIC
THERMOSTAT
I-42
I-42B-36
Pin number with ( ); RHD
A1 A2 A3 A4 A5 A6 A7 A8 A9A10 A11 A12 A13 A14 A15 A16B1 B2 B3 B4 B5 B6 B7 B8 B9B10 B11 B12 B13 B14 B15 B16E1 E2 E3 E4 E5 E6 E7 E8 E9E10 E11 E12 E13 E14 E15 E16F1 F2 F3 F4 F5 F6 F7 F8 F9F10 F11 F12 F13 F14 F15 F16
6VD1/6VE1 ENGINE
D08RY00295

00 Ð 28 SERVICE INFORMATION
MAGNETIC CLUTCH DOES NOT RUN
·TURN THE STARTER SWITCH ON AND START THE
ENGINE.
·TURN THE FAN SWITCH ON.
·DOES THE BLOWER MOTOR RUN?
YESNO
REFER TO THE DIAGNOSIS PROCEDURE FOR
ÒBLOWER MOTOR DOES NOT RUNÓ.·IS THE FUSE C-20 (10A) NORMAL?
YESNO
REPLACE THE FUSE.·DISCONNECT THE A/C SWITCH CONNECTOR AND
REMOVE THE A/C SWITCH.
·IS THE A/C SWITCH NORMAL?
YESNO
YESNO
REPAIR AN OPEN CIRCUIT BETWEEN THE
FUSE C-20 AND I23-2.·REINSTALL THE A/C SWITCH AND DISCONNECT THE DUAL
PRESSURE SWITCH (OR TRIPLE PRESSURE SWITCH) CON-
NECTOR C25.
·TURN THE A/C SWITCH ON.
·IS THE BATTERY VOLTAGE APPLIED AT HARNESS SIDE
CONNECTOR C25-1?
YESNO
REPLACE THE SWITCH.·RECONNECT THE CONNECTOR C25 AND DISCONNECT THE
A/C THERMO RELAY CONNECTOR X5.
·IS THERE CONTINUITY BETWEEN HARNESS SIDE CONNEC-
TOR C25-2 AND X5-1?
YESNO
REPAIR AN OPEN CIRCUIT BETWEEN I23-6
AND C25-1.·IS THE DUAL PRESSURE SWITCH (OR TRIPLE PRESSURE
SWITCH) NORMAL?
YESNO
REPAIR OR REPLACE THE SWITCH.·IS THE BATTERY VOLTAGE APPLIED AT HARNESS SIDE
CONNECTOR I23-2?

SERVICE INFORMATION 00 Ð 31
4JG2 ENGINE
123
45 6
RELAY; A/C
B-36C-20
(LHD) 10A
A/C FL-1
80A
MAIN
1
2
B-2
C-25
2
4
X-5
1
3
4
13
24
1
A/C SW.
FAN SW.
I-23
PRESSURE
SW.
RELAY;
THERMO
B-2
C-25E-3I-23
BATTERY
3
1
2ELECTRONIC
THERMOSTAT
1
E-3
MAGNETIC
CLUTCHMg
OFF
I-18
2
6
1
321123
12
34
121
213
5 46
I-18
X-5
B-1
(LHD)
(RHD)
B-1
1
2 34
W/ CONDENSER
FAN
I-42
I-42B-36
D08RY00169

00 Ð 32 SERVICE INFORMATION
MAGNETIC CLUTCH DOES NOT RUN
·ARE NO. C-20 (10A) FUSE AND NO. C-19 (25A) FUSES OK?
YESNO
REPLACE·ARE HEATER & A/C (B-36) AND THERMOSTAT (X-5)
RELAYS OK?
YESNO
REPLACE·IS PRESSURE SWITCH (DUAL PRESSURE SWITCH) OK?
YESNO
SWITCH DEFECTIVE OR INSUFFICIENT REFRIGERANT·ARE A/C SWITCH AND FAN CONTROL KNOB (FAN
SWITCH) OK?
YESNO
REPLACE·TURN THE IGNITION SWITCH ÒONÓ (ENGINE IS
RUNNING)
·A/C SWITCH AND FAN CONTROL KNOB (FAN SWITCH
ÒONÓ
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. E3-1
NOYES
MAGNETIC CLUTCH DEFECTIVE ·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. C25-1
YESNO
OPEN CIRCUIT BETWEEN NO. C-20 (10A) FUSE AND
NO. C25-1·DISCONNECT THERMO RELAY (X-5)
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE RELAY TERMINAL NO. X5-2
YESNO
OPEN CIRCUIT BETWEEN NO. C25-2 AND NO. X5-2 ·CHECK TO SEE IF VOLTAGE (APPROX. 10V) IS PRESENT
CHASSIS SIDE RELAY TERMINAL NO. X5-1 AND
NO. X5-3
CONTINUED NEXT PAGE

00 Ð 34 SERVICE INFORMATION
4JX1 ENGINE
123
45 6
RELAY; A/C
B-36C-20
10A
A/C FL-1
80A
MAIN
1
2
B-2
C-25
2
4
X-5
1
3
4
13
24
1
A/C SW.
FAN SW.
I-23
PRESSURE
SW.
RELAY;
THERMO
B-2
C-25I-23
BATTERY
1
E-27
MAGNETIC
CLUTCHMg
OFF
I-18
2
6
1
321123
12
34
12
213
5 46
I-18
X-5
B-1(LHD) (RHD)
3
1
2ELECTRONIC
THERMOSTAT
I-42
B-1
1
2 34
W/ CONDENSER
FAN
I-42B-36
E-27
11
D08RY00170

SERVICE INFORMATION 00 Ð 35
MAGNETIC CLUTCH DOES NOT RUN
·TURN THE STARTER SWITCH ON AND START THE
ENGINE.
·TURN THE FAN SWITCH ON.
·DOES THE BLOWER MOTOR RUN?
YESNO
REFER TO THE DIAGNOSIS PROCEDURE FOR
ÒBLOWER MOTOR DOES NOT RUNÓ.·IS THE FUSE C-20 (10A) NORMAL?
YESNO
REPLACE THE FUSE.·DISCONNECT THE A/C SWITCH CONNECTOR AND
REMOVE THE A/C SWITCH.
·IS THE A/C SWITCH NORMAL?
YESNO
YESNO
REPAIR AN OPEN CIRCUIT BETWEEN THE
FUSE C-20 AND I23-2.·REINSTALL THE A/C SWITCH AND DISCONNECT THE DUAL
PRESSURE SWITCH (OR TRIPLE PRESSURE SWITCH) CON-
NECTOR C25.
·TURN THE A/C SWITCH ON.
·IS THE BATTERY VOLTAGE APPLIED AT HARNESS SIDE
CONNECTOR C25-1?
YESNO
REPLACE THE SWITCH.·RECONNECT THE CONNECTOR C25 AND DISCONNECT THE
A/C THERMO RELAY CONNECTOR X5.
·IS THERE CONTINUITY BETWEEN HARNESS SIDE CONNEC-
TOR C25-2 AND X5-1?
YESNO
REPAIR AN OPEN CIRCUIT BETWEEN I23-6
AND C25-1.·IS THE DUAL PRESSURE SWITCH (OR TRIPLE PRESSURE
SWITCH) NORMAL?
YESNO
REPAIR OR REPLACE THE SWITCH.·IS THE BATTERY VOLTAGE APPLIED AT HARNESS SIDE
CONNECTOR I23-2?