Isuzu Trooper (2000 year). Service manual - part 40

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–129

Inspection of the Magnetic Clutch System

6VE1 Engine

D08RY00143

1A–130 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Condition

Possible cause

Correction

Magnetic clutch does not work

—

Refer to Chart A

Chart A: Magnetic Clutch Does Not work 

Step

Action

Value(s)

Yes

No

1

Is the fuse No.C–20 normal?

—

Go to Step 2

Replace the

fuse

2

Is the relay No.X–7 (compressor relay) No.X–5 (A/C
thermo relay) and No.B–36 (heater relay) normal?

—

Go to Step 3

Replace the

fuse

3

Is the thermo unit normal?

—

Go to Step 4

Replace the

thermo unit

4

Is the pressure switch normal?

—

Go to Step 5

Replace the

pressure

switch

5

1. Turn the ignition switch on. (the engine is run.) 
2. Push the air conditioner switch on.

Is the battery voltage applied between the harness side
connector terminal No.E3–1 and the ground?

—

Go to Step 6

Go to Step 7

6

Repair or replace the magnetic clutch.

Is the action complete?

—

Verify repair

—

7

Is there continuity between the harness side connector
terminal No.X7–4 and No.E3–1?

—

Go to Step 9

Go to Step 8

8

Repair an open circuit between terminal No.X7–4 and
No.E3–1.

Is the action complete?

—

Go to Step 7

—

9

Is the battery voltage applied between the harness side
connector terminal No.X7–2 and ground, No.X7–1 and
ground?

—

Go to Step 11

Go to Step 10

10

Repair an open circuit between terminal No.X7–2 and
fuse No.C–20, No.X7–1 and fuse No.C–20.

Is the action complete?

—

Go to Step 9

—

11

Is the battery voltage applied between the harness side
connector terminal No.I33–18 and ground?

—

Go to Step 13

Go to Step 12

12

Repair an open circuit between terminal No.I33–18 and
No.X7–3.

Is the action complete?

—

Go to Step 11

—

13

Is the battery voltage applied between the harness side
connector terminal No.C25–1 and ground?

—

Go to Step 15

Go to Step 14

14

Repair an open circuit between terminal No.C25–1 and
fuse No.C–20.

Is the action complete?

—

Go to Step 13

—

15

Is the battery voltage applied between the harness side
connector terminal No.X5–3 and ground, No.X5–2 and
ground?

—

Go to Step 17

Go to Step 16

16

Repair an open circuit between terminal No.X5–3 and
No.C25–2, No.X5–2 and fuse No.C–20.

Is the action complete?

—

Go to Step 15

—

17

Is the battery voltage applied between the harness side
connector terminal No.I32–14 and ground?

—

Go to Step 19

Go to Step 18

HEATING, VENTILATION AND AIR CONDITIONING (HVAC) 1A–131

Chart A: Magnetic Clutch Does Not work  (Cont’d)

Step

No

Yes

Value(s)

Action

18

Repair an open circuit between terminal No.X5–1 and
I32–14.

Is the action complete?

—

Go to Step 17

—

19

Is there continuity between the harness side connector
terminal No.I33–4 and ground?

—

Go to Step 21

Go to Step 20

20

Repair an open circuit between terminal No.I33–4 and
No.E19–1.

Is the action complete?

—

Go to Step 20

—

21

Dose the thermo relay “ON” when connecting ground to
the harness connector terminal No.H16–6?

—

Go to Step 23

Go to Step 22

22

Failure on the auto air conditioner control unit.

Is the action complete?

—

Verify repair

—

CAUTION: There are conditions which air
conditioner system dose not operate except trouble
as follows.
1. The throttle is griater than 90%.

2. The ignition voltage is below 10.5 volts.

3. The engine speed greater than 4500 RPM for 5

seconds or 5400 RPM.

4. The engine coolant temperature (ECT) is greater

than 257

°

F.

5. The intake air temperature (IAT) is less than 41

°

F.

6. The power steering pressure switch signals a

high pressure condition.

1A–132 HEATING, VENTILATION AND AIR CONDITIONING (HVAC)

Individual Inspection

In Car Sensor

1. Disconnect the in car sensor connector (I–34).
2. Measure resistance between the in car sensor side

terminal No.I34–3 and No.I34–4.

865RY00011

Sun Sensor

1. Disconnect the sun sensor connector (I–35).
2. Measure the current value on the sun sensor when

placed it approximately 15 cm away from 60W
incandescent lamp.

D06RY00001

Ambient Sensor

1. Disconnect the connector (C–86) on the ambient

sensor.

2. Measure resistance between the ambient sensor side

terminals. 

C01RY00006