engine ISUZU TROOPER 1998 Service Workshop Manual

1BÐ94 AIR CONDITIONING
Chart "A" : Check of Auto Amplifier Power Supply System
NOHarness disconnection or improper grounding.
NOHarness disconnection or improper grounding.
NOHarness disconnection or trouble on lighting
switch.
NOHarness disconnection or improper grounding.
Turn off ignition switch.
Power supply system is free of
trouble.
YES YES
YES YES
Is battery voltage present between chassis
harness connector terminal No.7
and ground?
I-32
Is battery voltage present between
chassis harness connector No.8
and ground?
I-32
Are chassis harness connector No.16
and body ground conducted?
B-18I-32
Turn on ignition switch (engine is started).
Turn on lighting switch.
Is battery voltage present between chassis
harness connector No.10 and
ground?
I-32

AIR CONDITIONING 1BÐ95
Performance and Movement checklist for Automatic Air Conditioner Related Parts
Start the engine, and when the engine coolant reached 60¡C check performance and movement of the
related parts according the following checklist.
1. Performance Check Using the Manual Switch
Checking ApproachNo.ItemAcceptance criteria
Condition Operation
Blowing
temperature
(check movement
of air mix door)
Airflow volume
(check movement
of the mode door)Set temperature to
25.0¡C.(1) Turn the fan knob
off.
(2) Turn the fan knob
from LOW to HI.(1) The fan shall be stopped, thus
stopping air blow, too.
(2) Airflow volume shall change
from LOW to HI.
Blowing
temperature
(check movement
of the mode door)Set temperature to
25.0¡C.
Set the fan knob to HI.Press the mode switch
to change the blow port
mode sequentially from
the VENT through BI-
LEVEL, FOOT up to
DEF.LED corresponding to each mode
shall be turned on and the blow
port mode shall be switched
smoothly.
The
interior/outside air
switching mode
(check movement
of intake door)Set temperature to
25.0¡C.Turn the LED off using
the interior/outside air
switch (this introduces
the outside air intake
mode). Then, the set
fan knob to HI and
press the
interior/outside switch
to turn on the LED.The LED indication shall be
switched from OFF to ON
accompanying a change in air
blowing sound.
Compressor Set the temperature to
FC. (Outside air
temperature is 0C or
above and interior
temperature at ordinary
temperature.)Press the "OFF" switch.
(1) Press the Auto
switch.
(2) Press the Air
Conditioner switch.(1) As the fan knob is set to the
Auto position, the A/C switch
LED shall come on and the
compressor shall be turned on.
(2) As the A/C LED comes off, the
compressor shall be turned off. Auto switch must be
turned on
(FAN-AUTO
MODE-AUTO)(1) Select FC for the
setup temperature.
(2) Select FH for the
setup temperature.
®Then, select the
MAX Control.(1) Cold air shall be blown out.
(2) Hot air shall be blown out.
1
2
3
4
5

1BÐ98 AIR CONDITIONING
*1. Displaying the Current Trouble Diagnosing Table
Start the engine while holding down both the Auto switch and the DEF switch on the control panel, and
the table will appear in approximately 10 seconds to the indicator lamp (LED) of the air conditioning
switch. Result of the diagnosis along the following 9 items will be shown one by one in 0.5 second
interval irrespective of presence or absence of a trouble for a given item. When the display 9 items is
completed, it is repeated with 3 seconds of interval in between. A failed item is indicated by flashing of
the LED that is repeated 3 times within 0.5 seconds. If a trouble is indicated, you can locate the failed
section by knowing when in the total sequence it has been displayed.
Items for Current Trouble Diagnosis
As shown above, display of result along nine items is repeated with 3-second interval in between.
Note 1: When checking the solar radiation sensor, apply sufficient light using a 60W bulb.
Otherwise, it can be diagnosed as failed.
Note 2: If the temperature setting lever is set on both ends (one set to 18¡C, blue scale = Full cool and
the other to 31¡C, red scale = Full hot), they can be diagnosed as failed.
Note 3: Likewise, the fan switch can be diagnosed as failed if set on both ends.
LED on
LED off Indication for presence
of a troubleIndication for normal state
0.5 0.5 0.5
3 seconds interval
ON
OFF
Display pattern Failed part
Normal pattern
In car sensor
Ambient sensor
Sun sensor (Note 1)
Duct sensor
Temperature control lever (Note 2)
Fan switch (Note 3)
Mix actuator
Mode (blow port) control
Intake (fresh air/interior air switching) control
F01RX010
F01RY00008

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