ISUZU TROOPER 1998 Service Repair Manual

AIR CONDITIONING 1BÐ115
Chart B: Fan Does Not Rotate in MAX HI Mode
NOThe harness is disconnected.
YES
NONONO YES
YES
YES
Turn on the ignition switch (the engine is
started).
Set the fan switch to the MAX HI.
The harness is
disconnected.Failure on the automatic
heater/air conditioner
control unit.
Failure on the MAX
HI relay.Failure on the
ground or the
harness is
disconnected.Is the battery voltage present between the
chassis harness side connector terminal
No.12 and the ground?
I-32
Are the chassis harness side connector
terminal No.4 and the body ground
(No. ) conducted?
B-1
I-51
Are the chassis harness side connector
terminals No.1 and No.2
conducted?I-51B-5
Is the battery voltage present between
the chassis harness side connector
terminal No.1 and No.3 d?
I-51I-51

1BÐ116 AIR CONDITIONING
Chart C: Fan Does Not Rotate In Any Mode Other Than MAX HI
NOReplace the power transistor.
NOFailure on the ground or the harness is
disconnected.
NOThe harness is disconnected.
NOThe harness is disconnected.
YES
YES YES
YES
Failure on the automatic heater/air
conditioner control unit.
Is the power transistor performance
normal? (Refer to the later section on
"Check Up".)
Is the battery voltage present between
the chassis harness side connector
terminal No.3 and the ground No.
?
B-1
I-50
Is conduction provided between the
following chassis harness side connector
terminals?
No.1 and No.1 .
No.1 and No.17 .
I-33B-5
I-50B-5
Are the chassis harness side connector
terminals No.2 and No.19
conducted?
I-33I-50

AIR CONDITIONING 1BÐ117
Chart D: Fan Does Not Stop
NOReplace the power transistor.
NOReplace the relay.
YES
NO YES
Turn on the ignition switch (the engine is
started).
YES
Is the power transistor performance
normal? (Refer to the later section on
"Check Up".)
Is the MAX HI relay performance
normal? (Refer to the later section on
"Check Up".)
Is the battery voltage present between
the chassis harness side connector
terminals No.1 and No.3 ?
I-51I-51
The chassis harness side connector
terminals No.1 and No.2 , or
No.1 and No.1 is short
circuited.
I-50B-5
I-51B-5
Failure on the automatic heater/air
conditioner control unit. Or, the harness
line is short circuited between the chassis
harness side connector terminals No.3
and No.12 .
I-32I-51

1BÐ118 AIR CONDITIONING
Inspection of the Magnet Clutch System
6VE1 Engine
I-32
C-1C-3I-33
E-3E-19
12345678
9 10111213141516
1
112
123
134
145
156
167
178
189
1910
20
B-19C-25
A 2
B-361
H-14
C-19
25A
BLOWER
MOTOR
C-20
10A
A/C FL-1
80A
MAIN
Heater
Relay
1B-3610
H-13
0.3
B 0.85
W/G0.85
W/R
3.0
W
3.0
L/R
0.5
BR
1.25
B
B-19
BODY-LH3
B-36
4B-36
BATT.(+)
Blower
MotorIntake
Actuator STARTER
RELAY(1)
0.5
LG 0.5
BR0.5
BR
0.5
G/W
0.5
P/G0.5
P/G0.5
G/O
0.5
G/O
PCM
(C3-E15)
31 13
COMP-F/B 70.5
BR
0.5
BR/Y 0.3
G/B0.5
G/B0.5
BR/Y 0.5
BR
Triple
Pressure
Switch
0.5
BR
A
A/C
Thermo Relay
Auto A/C Control Unit
3X-5
16
H-1617H-16
14
I-3218I-33
1X-5
13H-24
12
H-41
2 1
C-25
C-25
4X-5X-5 2
X-57
H-16
A/C
Compressor
Relay
Magnetic
clutch
1X-7
3X-74X-72
X-7
PCM
(C-1-B14)
E-39
1
H-67
H-41
5
H-41
Engine
Coolant
Temperature
Sensor
ENGINE COOLANT
TEMPERATURE GAUGE
0.5
Y/B
0.5
Y/B
0.5
Y/B
E-1911
1
H-61
H-24
I-334
B-36X-5X-7
H-14
1
2
1
2
H-16
H-24
H-13
H-6H-41
12
3412111
362
51
4 123
45 610987654321
22212019181514131211171612345111213141567891018192021221617
6H-41
4321
8765
12 11 10 9
16 15 14 13123 4
567 8
9101112
13 14 15 16
17 18 16 15 1478 6 5
12 13 11 10 94 132
5 6 7 8
15 16 17 18 142 3 41
10 11 12 13 9A1 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
D08RY00182

AIR CONDITIONING 1BÐ119
Chart A: Magnet Clutch Does Not work
NOThe harness is disconnected.
NOReplace the failed relay.
NOFailure on the power supply system.
NO
NO
NOReplace the fuse.
YESFailure on the magnet clutch.
NOReplace the electronic thermostat.
YES
YES YES
YES
YESNO
YES
The harness is disconnected.
Failure on the pressure switch or
refrigerant is insufficient.
Turn the A/C (air conditioner) switch on.
Are the pressure switch side connector
terminals No.1 and No.2
conducted?C-25C-25
Are relays normal?
Is fuse (C-20) 10A normal?
Is the electronic thermostat normal?
Is the battery voltage present between
the chassis harness side connector
terminal No.1 and the ground?
E-3
Is the battery voltage present between
the chassis harness side connector
terminal No.1 and the ground.
C-25
Is the battery voltage present between
the chassis side relay terminal No.3
and the ground, and No.1
and the ground?
X-7X-5
YES
Turn the ignition switch off.
Is conduction provided between the
following chassis harness side connecter
terminals?
No.2 and No.2 .
No.4 and No.1 .
E-3X-7
X-7X-5
Turn the ignition switch on (the engine is
started).
Magnet clutch does not work
Chart A
Type of trouble

1BÐ120 AIR CONDITIONING
NO
NOThe harness is disconnected.
YES YES
Failure on PCM (see Chapter 6E for A/C
control with PCM).
Is the battery voltage present between the
chassis harness side connector terminal
No.14 and the ground?
I-32
Is conduction provided between the
following chassis harness side connector
terminals?
No.B14 and No.3 .
No.E15 and No.4 .
X-5C-3
X-7C-1
Disconnect the connector on the
automatic heater/air conditioner control
unit.I-32
The harness is disconnected between No.1
and No.14 .I-32X-5
YESWhen you turned on the "Auto" switch,
does the battery voltage appear
between the chassis harness connector
terminal No.14 and the ground?
I-32
Failure on the automatic heater/air conditioner
control unit.
NO

AIR CONDITIONING 1BÐ121
4JX1 Engine
Magnet clutch does not work.
Chart A
Type of trouble
C-25
0.5 BR
C-25
X-5X-5
X-5X-5
2 1
4 3
0.5 P/G FL-1 MAIN
80A
C-20
10A A/C
0.5 G/W 0.5 G/O
C-25E-27H-16
Pressure
switch
Relay:
Air conditioning
thermostat
Automatic heater/air conditioner
control unitRelay:
Air conditioning
0.5 BR
1
2
I-3214
Fan “ON”
12
I-32X-5
12
34
E-271
Magnet
clutch
B-36
B-36
H-1616
1117 18 16 15 1478 6 5
12 13 11 10 94 132
5 6 7 8
15 16 17 18 142 3 41
10 11 12 13 9
12345678
9 10111213141516
D08RY00183

1BÐ122 AIR CONDITIONING
Chart A: Magnet Clutch Does Not Work
NOReplace the fuse.
NOReplace the failed relay.
NOReplace the electronic thermostat.
YESFailure on the magnet clutch.
NOThe harness is disconnected.
NOFailure on the power supply system.
YES
Is fuse C-20 (10A) normal?
Are relays normal?
YES
YES
Is the electronic thermostat normal?
YES
Turn the A/C (air conditioner) switch on.
Is the battery voltage present between the
chassis harness side connector terminal
No.1 and the ground?
E-27
NO
Is the battery voltage present between the
chassis harness side connector terminal
No.1 and the ground.
C-25
YES
NOFailure on the pressure switch or refrigerant is
insufficient.
NOThe harness is disconnected.Is the battery voltage present between the
chassis side relay terminal No.1
and the ground?X-5
Are the pressure switch side connector
terminals No.1 and No.2
conducted?C-25C-25
YES
YES
Failure on the automatic heater/air
conditioner control unit.
NOThe harness is disconnected.
Is conduction provided between the
chassis harness side connecter terminals
No.1 and No.4 ?
X-5E-27
YES
Are the chassis harness connector
terminals No.14 and No.3 ?X-5I-32

AIR CONDITIONING 1BÐ123
Inspection of the Air Conditioner Room Temperature Setup System
¥ Conflicts Between the Set Temperature and Actual Room Temperature
NOReplace the failed sensor.
NO
NO
Failure on the automatic heater/air
conditioner control unit.
YES YESYES
Is the in car sensor intaking the room
air? (Refer to the later section on "Check
Up".)
Is the air mix link properly attached?
(Make sure that selecting FH or FC using
the lever respectively sets the mix door
to the full hot or full cool.)
Are the interior temperature sensor and
the outside air temperature sensor
functioning normally?
Failure on the in car sensor.
Failure on the air mix link or the actuator.

1BÐ124 AIR CONDITIONING
INDIVIDUAL INSPECTION
In Car Sensor
1. Disconnect the in car sensor connector (I-34).
2. Measure resistance between the in car sensor
side terminal No.3 and No.4 .Sun Sensor
1. Disconnect the sun sensor connector (I-35).
2. Measure the current value on the sun sensor
when placed it approximately 15 cm away from
60W incandescent lamp.
Ambient Sensor
1. Disconnect the connector (C-86) on the ambient
sensor.
2. Measure resistance between the ambient
sensor side terminals. I-34
I-34
Temperature on the Sensor
Temperature Detector(¡C)
Sensor Resistance
Value(k½)














"650
4321
-20 0 5 10 15 20
25 30
-10 0 10 20 30 40
17.09
9.93
3.75
2.24
6.0
1.6 30.69
865RX007
½
0
10 0 -10 -20 30 4020 5 10 15 20 25 30
Temperature on the Sensor
Temperature Detector(¡C)
Sensor Resistance
Value(k½)
17.09 30.69
9.93
6.0
3.75
2.24
1.6
C01RX012
Ð Testing rod12
A
Current
value
40µA or more
+
12
21
D06RY00001