ignition ISUZU TROOPER 1998 Service User Guide

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.

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

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