Mitsubishi Montero (2004+). Manual - part 638

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-41

NOTE: Also check intermediate connector D-28, joint connec-
tor (2) A-15, junction block connectors D-210 and D-208. If 
intermediate connector D-28, joint connector (2) A-15, junction 
block connectors D-210 or D-208 is damaged, repair or replace 
the connector as described in GROUP 00E, Harness Connec-
tor Inspection 

P.00E-2

.

Q: Is the wiring harness between A/C compressor clutch 

relay connector A-12X (terminal 3) and the ignition 
switch (IG2) in good condition?
YES : Check that the air conditioning works normally.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

AC204167

CONNECTOR : A-15

AD

14

13

4

1112

5

3

10

8 9

2

7

1

6

AC204170

CONNECTOR : D-28

AI

2 3

27

32

28

33

16

15

4 5

19

18

29

17

34

7 8

35

22

21

9 10

30

36

31

37

25

24

23

6

20

1

14

26

11

13

12

38

AC204191

CONNECTORS: D-208, D-210

D-208

AC

HARNESS SIDE

HARNESS SIDE

D-210

D-208

D-210

1

2

3

5

6

4

1

2

7 6

3

9

4

11

12

10

13

5

8

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-42

STEP 12. Measure the voltage at A/C compressor clutch 
relay connector A-12X. 
(1) Disconnect A/C compressor connector A-12X and measure 

the voltage at the relay box side.

(2) Measure the voltage between terminal 5 and ground.

• The measured value should be approximately 12 volts 

(battery positive voltage).

Q: Does the measured voltage correspond with this range?

YES :  Go to Step 15.
NO :   Go to Step 13.

STEP 13. Check A/C compressor clutch relay connector 
A-12X for damage.

Q:  Is A/C compressor clutch relay connector A-12X in 

good condition?
YES : Go to Step 14.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

STEP 14. Check the wiring harness between A/C 
compressor clutch relay connector A-12X (terminal 5) and 
the fusible link (1).

Q: Is the wiring harness between A/C compressor clutch 

relay connector A-12X (terminal 5) and the fusible link 
(1) in good condition?
YES : Check that the air conditioning works normally.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

AC204183

CONNECTOR : A-12X

AP

RELAY BOX
SIDE

2 1

5

4

3

AC204738 CW

RELAY BOX SIDE : A-12X

2 1

5

4

3

AC204183

CONNECTOR : A-12X

AP

RELAY BOX
SIDE

2 1

5

4

3

AC204183

CONNECTOR : A-12X

AP

RELAY BOX
SIDE

2 1

5

4

3

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-43

STEP 15. Check A/C compressor clutch relay connector 
A-12X and A/C compressor connector B-30 for damage.

Q:  Is A/C compressor clutch relay connector A-12X and 

A/C compressor connector B-30 in good condition?
YES : Go to Step 16.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

STEP 16. Check the wiring harness between A/C 
compressor clutch relay connector A-12X (terminal 4) and 
A/C compressor connector B-30 (terminal 3).

AC204183

CONNECTOR : A-12X

AP

RELAY BOX
SIDE

2 1

5

4

3

AC204169

CONNECTOR : B-30

AE

B-30(B)

B-30(B)

2

3

1

HARNESS 
SIDE

AC204183

CONNECTOR : A-12X

AP

RELAY BOX
SIDE

2 1

5

4

3

AC204169

CONNECTOR : B-30

AE

B-30(B)

B-30(B)

2

3

1

HARNESS 
SIDE

AUTO A/C DIAGNOSIS

TSB Revision

AUTOMATIC AIR CONDITIONING

55B-44

NOTE: Also check intermediate connector A-05. If intermediate 
connector A-05 is damaged, repair or replace the connector as 
described in GROUP 00E, Harness Connector Inspection 

P.00E-2

.

Q: Is the wiring harness between A/C compressor clutch 

relay connector A-12X (terminal 4) and A/C compressor 
connector B-30 (terminal 3) in good condition?
YES : Go to Step 17.
NO :  Repair the wiring harness. Check that the air 

conditioning works normally.

STEP 17. Check powertrain control module connector 
D-132 and A/C compressor clutch relay connector A-12X 
for damage.

Q:  Are powertrain control module connector D-132 and 

A/C compressor clutch relay connector A-12X in good 
condition?
YES : Go to Step 18.
NO :  Repair or replace the connector. Refer to GROUP 

00E, Harness Connector Inspection 

P.00E-2

. Check 

that the air conditioning works normally.

AC204167

CONNECTOR : A-05

BC

A-05(B)

A-05(B)

8

4

7

3

5

1

6

2

AC204183

CONNECTOR : A-12X

AP

RELAY BOX
SIDE

2 1

5

4

3

AC204171

CONNECTOR : D-132

D-132(GR)

D-132(GR)

AS

HARNESS SIDE

8

23

1110

24

9

6

22

7

16

17

15

3

4

1312

19

20
2726

2

1
5

14
21

25

18