Isuzu 2000 Trooper Workshop Manual page 145

1A–116 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)
Condition
Does not work at all
Control failure
Chart A: Does Not Work At All
Step
1 Is the fuse FL–1 normal?
2 Is the fuse C–20 normal?
3 Is the relay B–36 normal?
4 Turn on the ignition switch. (the engine is run.)
Is the battery voltage applied between the harness side
connector terminal No.I49–3 and ground?
5 Repair an open circuit between terminal No.I49–3 and
No.B36–4.
Is the action complete?
6 Is the battery voltage applied between the harness side
connector terminal No.I49–4 and ground?
7 Replace the intake actuator motor.
Is the action complete?
8 Is there continuity between the harness side connector
terminal No.I32–11 and No.B49–4?
9 Repair an open circuit between No.I32–11 and I49–4.
Is the action complete?
10 Replace the auto air conditioner control unit.
Is the action complete?
Possible cause
—
—
Action
Correction
Refer to Chart A
Refer to Chart B
Value(s) Yes
— Go to Step 2
— Go to Step 3
— Go to Step 4
Approx 12V Go to Step 6
— Go to Step 4
Approx 12V Go to Step 8
— Go to Step 6
— Go to Step 10
— Verify repair
— Verify repair
No
Replace the
fuse
Replace the
fuse
Replace the
relay
Go to Step 5
—
Go to Step 7
—
Go to Step 9
—
—