Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 35

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–111

Condition

Possible cause

Correction

The fan dose not rotate at all

—

Refer to 

Chart A

The fan dose not rotate in the
MAX–HI mode

—

Refer to 

Chart B

The fan dose not rotate in any mode
other than MAX–HI

—

Refer to 

Chart C

The fan dose not stop

—

Refer to 

Chart D

Chart A: Fan Does Not Rotate At All 

Step

Action

Value(s)

Yes

No

1

Are the fuse No.F–5, F–6 and No.F–7 normal?

—

Go to 

Step 2

Replace the

fuse

2

Are the relay No.X–1 and No.C–35 normal?

—

Go to 

Step 3

Replace the

relay

3

Turn on the ignition switch (the engine is run).

Is the battery voltage applied between the harness side
connector terminal No.C36–1 and ground?

—

Go to 

Step 5

Go to 

Step 4

4

Repair an open circuit between terminal No.C36–1 and
No.F–5 and F–6 fuse.

Is the action complete?

—

Go to 

Step 3

—

5

Is there continuity between the harness side connector
terminal No.C36–2 and ground (No.C–10)?

—

Go to 

Step 7

Go to 

Step 6

6

Repair an open circuit between terminal No.C36–2 and
ground.

Is the action complete?

—

—

—

7

Is the battery voltage applied between the harness side
connector terminal No.C36–2 and No.C36–1?

—

Go to 

Step 8

Go to 

Step 9

8

Replace the blower motor.

Is the action complete?

—

Verify repair

—

9

Refer to 

chart B and C.

Is the action complete?

—

Verify repair

—

1A–112 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Chart B: Fan Does Not Rotate in MAX HI Mode 

Step

Action

Value(s)

Yes

No

1

Is the MAX-HI relay (C–35) normal?

—

Go to 

Step 2

Replace the

relay

2

1. Turn on the ignition switch (the engine is run).
2. Set the fan switch to the MAX-HI.

Is there continuity between the harness side connector
terminal No.C36–2 and No.C35–5?

—

Go to 

Step 4

Go to 

Step 3

3

Repair an open circuit between terminal No.C36–2 and
No.C35–5.

Is the action complete?

—

Go to 

Step 3

—

4

Is there continuity between the harness side connector
terminal No.C35–1 and ground (No.C–10)?

—

Go to 

Step 6

Go to 

Step 5

5

Repair an open circuit between terminal No.C35–1 and
ground (No.C–10).

Is the action complete?

—

Go to 

Step 4

—

6

Is the battery voltage applied between the harness side
connector terminal No.C35–2 and ground?

—

Go to 

Step 8

Go to 

Step 7

7

Repair an open circuit between terminal No.C35–2 and
No.F–7 fuse.

Is the action complete?

—

Go to 

Step 6

—

8

Is the battery voltage applied between the harness side
connector terminal No.I19–2 and ground?

—

Go to 

Step 10

Go to 

Step 9

9

Repair an open circuit between terminal No.C35–4 and
No.I19–2.

Is the action complete?

—

Verify repair

—

10

Replace the auto air conditioner control unit.

Is the action complete?

—

Verify repair

—

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–113

Chart C: Fan Does Not Rotate In Any Mode Other Than MAX HI 

Step

Action

Value(s)

Yes

No

1

Is the power transistor performance normal? (Refer to
the 

later section on “individual inspection”)

—

Go to 

Step 2

Replace the

power

transistor

2

Is there continuity between the harness side connector
terminal No.C36–2 and No.C34–1, No.C36–2 and
No.I20–17?

—

Go to 

Step 4

Go to 

Step 3

3

Repair an open circuit between terminal.

No.C36–2 and C34–1
No.C36–2 and I20–17

—

Go to 

Step 2

—

4

Is there continuity between the harness side connector
terminal No.C34–3 and ground (No.C–10)?

—

Go to 

Step 6

Go to 

Step 5

5

Repair an open circuit between terminal No.C34–3 and
ground.

Is the action complete?

—

Go to 

Step 4

—

6

Is there continuity between the harness side connector
terminal No.C34–2 and No.I20–19?

—

Go to 

Step 8

Go to 

Step 7

7

Repair an open circuit between terminal No.C34–2 and
No.I20–19.

Is the action complete?

—

Go to 

Step 6

—

8

Replace the auto air conditioner control unit.

Is the action complete?

—

Verify repair

—

1A–114 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Chart D: Fan Does Not Stop 

Step

Action

Value(s)

Yes

No

1

1. Disconnect the max high relay, the power transistor

connector C–34 and the auto A/C control unit
connector I–20.

2. Turn on the ignition switch.

Does the blower motor stop?

—

Go to 

Step 3

Go to 

Step 2

2

Repair a short circuit between connector No.C36–2
and No.C35–5, No.C36–2 and No.C34–1, or
No.C36–2 and I20–17.

Is the action complete?

—

Verify repair

—

3

Is the max high relay normal? (Refer to the 

later section

on “individual inspection”.)

—

Go to 

Step 4

Replace the

relay

4

Reinstall the max high relay.

Does the blower motor start operating?

—

Go to 

Step 6

Go to 

Step 5

5

Repair a short circuit between connector No.C35–4
and No.I19–2.

Is the action complete?

—

Go to 

Step 4

—

6

Is the power transistor normal? (Refer to the 

later

section on “individual inspection”.)

—

Go to 

Step 7

Replace the

power

transistor

7

Reinstall the power transistor.

Does the blower motor start operating?

—

Replace the

auto A/C

control unit

—