1998 ISUZU TROOPER engine

AIR CONDITIONING 1BÐ109
Chart B: Mix Actuator Control Failure
NOReplace the actuator.
NOThe harness is disconnected.
NO
NOMix actuator control failure due to the
failed sensor.
YES YES
YES
YES
Turn on the ignition switch (the engine is
started).
Replace the automatic heater/air conditioner
control unit.
Is conduction provided between the
following chassis harness side
connector terminals?
No.3 and No.11 .
No.7 and No.5 .
No.2 and No.15 .
I-33I-45
I-33I-45
I-33I-45
Is sum of the voltages between the
following chassis harness side connector
terminals approximately 5V?
Voltage between No.15 and No.5
plus voltage between No.5
and No.11 .
I-33
I-33I-33
I-33
Does the self-diagnosis function (the
current trouble display) indicate failure
on the mix actuator potentiometer?
Is full stroke of the air mix door available
when you selected FH or FC using the
temperature control lever?Failure on the air mix door or the link
unit.

AIR CONDITIONING 1BÐ111
Chart A: Does Not Work At All
NOThe harness is disconnected.
NOReplace the automatic heater/air
conditioner control unit.
NOReplace the automatic heater/air
conditioner control unit.
YES YES
YES
Turn on the ignition switch (the engine is
started).
Disconnect the mode actuator connector
(B-69).
Select VENT pushing the mode actuator
switch.
Turn on the DEF mode switch.
Failure on the actuator.
Is the battery voltage provided on a
regular interval between the following
chassis side connector terminals?
No.3 (+) and No.4 (-).
I-32I-32
Is conduction provided between the
following chassis harness side connector
terminal?
No.1 and No.4 .
No.5 and No.3 .
I-32B-69
I-32B-69
Is the battery voltage provided on a
regular interval between the following
chassis harness side connector
terminals?
No.4 (+) and No.3 (-).
I-32I-32

1BÐ112 AIR CONDITIONING
Chart B: Mode Actuator Control Failure
NOThe harness is disconnected.
NOReplace the actuator.
NOFailure on the mode door or the link unit.
YESMode control failure due to the failed
sensor.
NO YES
YES
YES
Turn on the ignition switch (the engine is
started).
Replace the automatic heater/air conditioner
control unit.
Is conduction provided between the
following chassis harness side
connector terminals?
No.9 and No.11 .
No.3 and No.10 .
No.4 and No.8 .
I-33B-69
I-33B-69
I-33B-69
Is sum of the voltages between the
following chassis harness side connector
terminals approximately 5V?
Voltage between No.15 and No.1
plus voltage between No.15
and No.11 .
I-33
I-32I-32
I-32
Does the mode work normally through
manual operation?
Is full stroke available from the mode
door when the defrost mode and vent
mode are selected?

1BÐ114 AIR CONDITIONING
Chart A: Fan Does Not Rotate At All
NOFailure on the power supply system.
NOFailure on the ground or the harness is
disconnected.
NOReplace the fan motor.
YES
YES YES
Turn on the ignition switch (the engine is
started).
Refer to Charts B and C.
Is the battery voltage present between the
chassis harness side connector terminal
No.2 and the ground?
B-5
Are the chassis harness side connector
terminals No.4 and the ground
(No. ) conducted?
B-1
I-51
Is the battery voltage present between
the chassis harness side connector
terminals No.1 and No.2 ?
B-5B-5
Type of trouble
The fan does not
rotate in any mode
other than MAX HI.The fan does not stop.
Chart BChart CChart D
The fan does not
rotate in the MAX HI
mode.The fan does not
rotate at all.
Chart A

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

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