1998 ISUZU TROOPER heater

1BÐ102 AIR CONDITIONING
Chart 2: Ambient Sensor
NOReplace the ambient sensor.
NOFailure on the harness.
Connect the ambient sensor connector.
Replace the automatic heater/air conditioner
control unit.
YES
Disconnect the Ambient sensor connector
(C-86).
YES
Is performance of the ambient sensor
normal? (Refer to the later section on
"Check Up".)
Is resistance between the following
connectors normal?
No.2 and No.11 .
I-33I-33
I-33C-86
H-24
1
112
123
134
145
156
167
178
189
1910
20
0.3 LG/B
0.3 B/L
112
Ambient Sensor Auto A/C Control Unit
(Ambient Sensor)
(Sensor GND)I-330.3 LG/B
0.3 B/LH-24 8
H-24 9
C-86 1
C-86 2
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 9
12
D08RY00176

AIR CONDITIONING 1BÐ103
Chart 3: Sun Sensor
NOReplace the sun sensor.
NOReplace the harness.
Replace the automatic heater/air conditioner
control unit.
YES
Disconnect the sun sensor connector (I-35).
YES
Is performance of the sun sensor normal?
(Refer to the later section on "Check Up".)
Is the conduction provided between the
following chassis harness side connector
terminals?
No.3 and No.1 .
No.11 and No.2 .
I-35I-33
I-35I-33
0.3 LG/W
0.3 B/L
113
Sun Sensor Auto A/C Control Unit
(Sun Sensor)
(Sensor GND)I-33I-351
I-352
I-33I-35
211
112
123
134
145
156
167
178
189
1910
20
D08RY00177

AIR CONDITIONING 1BÐ105
Chart A: Does Not Work At All
NOFailure on the power supply circuit.
NOFailure on the actuator.
NOThe harness is disconnected.
NOReplace the automatic heater/air conditioner
control unit.
YES
YES YES
YES
Turn on the ignition switch (the engine is
started).
Switch between the fresh air intake and the
interior air circulation.
Failure on the intake link unit (intake door
lock).
Is the battery voltage present between the
chassis harness side connector terminal
No.3 and the ground?
I-49
Is the battery voltage present between
the chassis harness side connector
terminal No.4 and the ground?
I-49
Is the battery voltage present between
the chassis harness side connector
terminal No.11 and the ground?
I-32
During the above switch operations, did
the voltage between the chassis harness
side connector terminal No.11 and
the ground go below 0.5V?
I-32

1BÐ106 AIR CONDITIONING
Chart B: Failure on the Intake Control
NOThe harness is disconnected.
NOFailure on the automatic heater/air
conditioner control unit.
NOFailure on the automatic heater/air
conditioner control unit.
YES YES
YES
Turn on the ignition switch (the engine is
started).
Disconnect the intake actuator connector
(I-49).
Failure on the intake actuator.
Is the intake actuator stopped?
Is conduction provided between the
following chassis harness side connector
terminals?
No.5 and No.11 .
No.6 and No.12 .
No.1 and No.13 .
No.2 and No.14 .
I-33I-49
I-33I-49
I-33I-49
I-33I-49
Is voltage (approximately 5V) present
between the following?
No.12 and the ground.
No.13 and the ground.
No.14 and the ground.
I-33
I-33
I-33

1BÐ108 AIR CONDITIONING
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 mix actuator connector
.
Short-circuit he chassis harness side
connector terminal No.3 and No.7
.
I-45I-45
I-45
Using the temperature control lever,
select FC for the temperature.
Using the temperature control lever,
select FC for the temperature.
Failure on the actuator.
Is the battery voltage present on a regular
interval basis between the chassis
harness side connector terminals No.6
(+) and No.5 (-)?
I-32I-32
Is conduction provided between the
following chassis harness side connector
terminals?
No.6 and No.6 .
No.5 and No.8 .
I-45I-32
I-45I-32
Is the battery voltage present on a regular
interval basis between the chassis
harness side connector terminals No.6
(-) and No.5 (+)?
I-32I-32

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.

1BÐ110 AIR CONDITIONING
Inspection of the Mode Actuator System
H-26
10 11 12 13 14 151234 5
17 18 19 206789
16
9876
20 19 18 17 165
14 154
133
122
111
10
H-25
I-32I-33
12345678
9 101112131415161
112
123
134
145
156
167
178
189
1910
20
I-320.3Y/BR 0.3Y/BR
B-69
I-33
10
9
8
7
11
6 3 ¢DEF TO VENT£
y´ VENT side
y´ DEF side
MODE1
MODE2
MODE3
MODE4
MODE5
S.GND4
1
2
3
4
20
5 26 2511
0.5Y/G 0.3Y/G12
0.3GR 0.3GR0.3GR/G
18
0.5GR/R 0.5GR/R19
0.5GR/G 0.3GR/G5
0.3GR/L 0.3GR/L1
0.5B/L 0.3B/L4
Auto A/C Control Unit
M
1
5
4
3
8
7
2
6
9
VENT
FOOT
DEF B/L
D/F
Mode Actuator
(Heater Unit)
¢VENT TO DEF£
H-25
H-25
H-26
H-26
H-25
H-26
H-26
0.5B/L 8
H-25
B-69
12
5634
89 7
10987654321
222120191815141312111716
12345111213141567891018192021221617
Type of the
trouble
Control failure.
Chart B
Does not work at all.
Chart A
D08RY00180

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