ISUZU TROOPER 1998 Service Manual PDF

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

SERVICE INFORMATION 00 Ð 33
CONTINUED PREVIOUS PAGE
NOYES
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE RELAY TERMINAL NO. X5-1OPEN CIRCUIT BETWEEN NO. X5-4 AND NO. E3-1
YESNO
·RECONNECT THERMO RELAY
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. I42-3
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. I23-2
NOYES
OPEN CIRCUIT BETWEEN
NO. C-20 (10A) FUSE AND
NO. I23-2OPEN CIRCUIT BETWEEN
X5-1 AND NO. I23-6NOYES
·CHECK TO SEE IF BATTERY VOLTAGE (APPROX. 10V)
IS PRESENT AT CHASSIS SIDE CONNECTOR TERMINAL
NO. I42-1
YESNO
·CHECK TO SEE IF BATTERY VOLTAGE IS PRESENT AT
CHASSIS SIDE CONNECTOR TERMINAL NO. I42-2OPEN CIRCUIT BETWEEN NO. X5-3 AND NO. I42-1
YESNO
·OPEN CIRCUIT BETWEEN NO. I42-2 AND NO. I18-4 OR
POOR GROUND (FAN SWITCH GROUND CIRCUIT)ELECTRO THERMO DEFECTIVE
OPEN CIRCUIT BETWEEN
NO. I23-6 AND NO. I42-3

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?

00 Ð 36 SERVICE INFORMATION
·IS THE BATTERY VOLTAGE APPLIED AT HARNESS SIDE
CONNECTOR X5-2?REPAIR AN OPEN CIRCUIT.
YESNO
·IS THE A/C THERMO RELAY NORMAL?REPAIR AN OPEN CIRCUIT BETWEEN THE
FUSE C-20 AND X5-2.
YESNO
·DISCONNECT THE ELECTRONIC THERMOSTAT CONNEC-
TOR I42.
·IS THE BATTERY VOLTAGE APPLIED AT HARNESS SIDE
CONNECTOR I42-3?
YESNO
·IS THERE CONTINUITY BETWEEN HARNESS SIDE CON-
NECTOR X5-3 AND I42-1?REPAIR AN OPEN CIRCUIT BETWEEN I23-6
AND I42-3.
YESNO
REPAIR AN OPEN CIRCUIT.
YESNO
·IS THERE CONTINUITY BETWEEN HARNESS SIDE CON-
NECTOR I42-2 AND THE GROUND?REPAIR AN OPEN CIRCUIT.
REPLACE THE RELAY.
·DIS CONNECT THE MAGNETIC CLUTCH CONNECTOR E27.
·CONNECT THE BATTERY WITH MAGNETIC CLUTCH SIDE
CONNECTOR E27-1.
·DOES THE MAGNETIC CLUTCH.
YESNO
REPAIR OR REPLACE THE MAGNETIC CLUTCH.·REPAIR AN OPEN CIRCUIT BETWEEN X5-4 AND E27-1.

SERVICE INFORMATION 00 Ð 37
CONDENSER FAN
When the cycling switch, which controls the
condenser fan of the triple pressure switch while
the A/C switch is on, senses the refrigerant pressureand the condenser fan turns on, the motor operates
via the condenser fan relay.
123
45 6
4
13
24
1
FAN SW.
B-2
OFF
I-18
I-18
B-1
(LHD)
(RHD)
X-19
1
3
4
5
RELAY;
CONDENSER
FAN
4TRIPLE
PRESSURE
SWITCH
3
1CONDENSER
FAN
2M
C-75 C-39
C-25
FL-4
30A
CONDENSER FANFL-1
80A
MAIN
2
6
1
I-23
RELAY; A/C
A/C SWITCH
2
C-39C-75C-25
I-23X-19
123 4
567 843
872
61
5
121 21
2 34
213
5 4612
34
D08RWD70

00 Ð 38 SERVICE INFORMATION
CONDENSER FAN DOES NOT RUN
YESNO
·DOES A/C SYSTEM OPERATE CORRECTLY?
·IS FL-4 (30A) FUSE OK?CHECK A/C SYSTEM AND REPAIR AS NECESSARY
YESNO
·IS CONDENSER FAN RELAY (X-19) OK?REPLACE
REPLACE
YESNO
·IS TRIPLE PRESSURE SWITCH (CYCLING SWITCH SIDE)
OK?
REPLACE
YESNO
·IS CONDENSER FAN MOTOR OK?
REPLACE
YESNO
·CHECK TO SEE IF CONTINUITY BETWEEN FL-4 (30A)
FUSE AND CHASSIS SIDE RELAY TERMINAL NO. X19-1.
REPLACE
YESNO
·CHECK TO SEE IF CONTINUITY BETWEEN CHASSIS SIDE
CONNECTOR TERMINAL NO. I23-6 AND NO. C25-3.
OPEN CIRCUIT
YESNO
·CHECK TO SEE IF CONTINUITY BETWEEN CHASSIS SIDE
CONNECTOR TERMINAL NO. C25-4 AND CHASSIS SIDE
RELAY TERMINAL NO. X19-4.
OPEN CIRCUIT
YESNO
·CHECK TO SEE IF CONTINUITY BETWEEN CHASSIS SIDE
RELAY TERMINAL NO. X19-5 AND CHASSIS SIDE
CONNECTOR TERMINAL NO. I18-4.
OPEN CIRCUIT
YESNO

SERVICE INFORMATION 00 Ð 39
·CHECK TO SEE IF CONTINUITY BETWEEN CHASSIS SIDE
RELAY TERMINAL NO. X19-3 AND CHASSIS SIDE
CONNECTOR TERMINAL NO. C75-1.
YESNO
OPEN CIRCUITPOOR GROUND OR OPEN CIRCUIT BETWEEN CHASSIS
SIDE CONNECTOR TERMINAL NO. C75-2 AND BODY
GROUND (NO. C39-7)
CONDENSER FAN DOES NOT STOP
·IS CONDENSER FAN RELAY (X-19) OK?
YESNO
REPLACETRIPLE PRESSURE SWITCH (CYCLING SWITCH SIDE)
DEFECTIVE
REPLACE TRIPLE PRESSURE SWITCH

00 Ð 40 SERVICE INFORMATION
1. Defective rotor/piston
2. Defective bearing (DKS-15CH)
3. Defective shaft
1. Defective bearing
2. Defective clutch
3. Clearance between drive plate
and pulley not standard
1. Defective gasket
2. Defective rotor/reed valve
3. Defective trigger valve/suction
valve
1. Defective rotor/piston
2. Defective shaft
3. Rotating parts seized due to
insufficient oil
1. Defective seal
2. Defective O-ringReplace compressor/cylinder and
shaft assembly
Replace cylinder and shaft assembly
Replace compressor/cylinder and
shaft assembly
Replace magnetic clutch
Replace magnetic clutch
Adjust the clearance or replace
magnetic clutch
Replace compressor/gasket
Replace compressor/valve plate
Replace compressor/suction valve
Replace compressor/cylinder and
shaft assembly
Replace compressor/cylinder and
shaft assembly
Replace compressor
Replace compressor/shaft seal
Replace Noise from compressor
Noise from magnetic
clutch face
Insufficient cooling
Not rotating
Oil and/or gas leakage 1
2
3
4
5
ITEM PROBLEM POSSIBLE CAUSES CORRECTION
COMPRESSOR TROUBLESHOOTING

SERVICE INFORMATION 00 Ð 41
I-18 I-23
123456126
OFF
1
FAN SW. 2
3
4
OFF
A/C SW.
ON
FAN CONTROL KNOB (FAN SWITCH) AND A/C
SWITCH
INDIVIDUAL INSPECTION
Check for continuity between fan switch and A/C switch
side connector terminals.
2
65 4 31362
51
4

I-23I-18
I-23I-18
5
A/C SW. BEZEL
ILLUMI-
NATION
FAN SW. OFF1
2
3
4 32 6 1253641
HEATER & A/C, THERMOSTAT, COMPRESSOR,
CONDENSER FAN AND CERAMIC HEATER RELAY
Check for continuity between the relay terminals.
2Ð 4..... No continuity
(When battery voltage is applied between 1Ð 3)
2Ð 4..... Continuity
2
2
1
144
3
3
Terminal
No. SW.
position
DUAL PRESSURE SWITCH
21
Disconnect pressure switch connector and check for
continuity between pressure switch side connector
terminals.