Mitsubishi L200. Manual — part 880

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-49

Inspection Procedure 5: The A/C compressor does not work

Wire colour code
B : Black LG : Light green G : Green L : Blue W : White Y : Yellow SB : Sky blue
BR : Brown O : Orange GR : Grey R : Red P : Pink V : Violet PU : Purple SI : Silver

A/C Compressor and Clutch Assembly Circuit

IGNITION
SWITCH (IG2)

RELAY
BOX

A/C COMPRESSOR
RELAY

A/C
COMPRESSOR
AND CLUTCH
ASSEMBLY

ENGINE-ECU

FUSIBLE
LINK

20

A/C
COMPRESSOR
CLUTCH ASSEMBLY

COMMENTS ON TROUBLE SYMPTOM
If the A/C compressor does not work, inadequate
refrigerant quantity or the A/C compressor circuit is
suspected..

POSSIBLE CAUSES

• Malfunction of A/C compressor

• Malfunction of A/C compressor relay

• Damaged harness wires and connectors

• Malfunction of engine-ECU

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-50

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-33 A/C compressor
connector and C-105 engine-ECU

AC509975AT

Harness side

Connector: A-33

A-33 (B)

AC509613 CD

Harness side

C-105 (B)

Connector: C-105 <LHD>

35

40

41

42

1817

38

39

15

16

14

3736

12

13

11

32

8

3433

9

10

30

31

7 6

29

5

4

28

3

27

2

26

1

25

19
43

2120

22

23

46

47

4544

24
48

76

52

86

62

63

64

65

66

67

68

69

70

71

72

92

95

96

93

94

89

90

91

8887

53

54

55

56

57

58

59

60

61

83

8584

8281

78

79

80

77

49

50

51

74

75

73

AC509930 CA

C-105 (B)

Connector: C-105 <RHD>

Harness side

35

40

41

42

1817

38

39

15

16

14

3736

12

13

11

32

8

3433

9

10

30

31

7 6

29

5

4

28

3

27

2

26

1

25

19
43

2120

22

23

46

47

4544

24
48

76

52

86

62

63

64

65

66

67

68

69

70

71

72

92

95

96

93

94

89

90

91

8887

53

54

55

56

57

58

59

60

61

83

8584

8281

78

79

80

77

49

50

51

74

75

73

Q: Is the check result normal?

YES :

Go to Step 2.

NO :

Repair the connector.

STEP 2. Voltage measurement at A-33 A/C
compressor connector.

AC509975AT

Harness side

Connector: A-33

A-33 (B)

(1) Disconnect the connector, and measure at the

wiring harness side.

(2) Turn the ignition switch to the "ON" position.

AC509613 CD

Harness side

C-105 (B)

Connector: C-105 <LHD>

35

40

41

42

1817

38

39

15

16

14

3736

12

13

11

32

8

3433

9

10

30

31

7 6

29

5

4

28

3

27

2

26

1

25

19
43

2120

22

23

46

47

4544

24
48

76

52

86

62

63

64

65

66

67

68

69

70

71

72

92

95

96

93

94

89

90

91

8887

53

54

55

56

57

58

59

60

61

83

8584

8281

78

79

80

77

49

50

51

74

75

73

AC509930 CA

C-105 (B)

Connector: C-105 <RHD>

Harness side

35

40

41

42

1817

38

39

15

16

14

3736

12

13

11

32

8

3433

9

10

30

31

7 6

29

5

4

28

3

27

2

26

1

25

19
43

2120

22

23

46

47

4544

24
48

76

52

86

62

63

64

65

66

67

68

69

70

71

72

92

95

96

93

94

89

90

91

8887

53

54

55

56

57

58

59

60

61

83

8584

8281

78

79

80

77

49

50

51

74

75

73

ACA00423

35

40

41

42

1817

38

39

15

16

14

3736

12

13

11

32

8

3433

9

10

30

31

7 6

29

5

4

28

3

27

2

26

1

25

19
43

2120

22

23

46

47

4544

24
48

76

52

86

62

63

64

65

66

67

68

69

70

71

72

92

95

96

93

94

89

90

91

8887

53

54

55

56

57

58

59

60

61

83

8584

8281

78

79

80

77

49

50

51

74

75

73

Connector C-105
(Harness side)

AB

(3) Disconnect engine-ECU connector C-105 and

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-51

earth terminal 19.

AC310507

Connector A-33
(Harness side)

JO

AC310507

(4) Voltage between terminal 1 and body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 11.

NO :

Go to Step 3.

STEP 3. Connector check: A-21X A/C
compressor relay connector

AC510163

AE

Connector: A-21X

Relay box side

Q: Is the check result normal?

YES :

Go to Step 4.

NO :

Repair the connector.

STEP 4. Check the A/C compressor relay
continuity.
Refer to .

Q: Is the A/C compressor relay in good condition?

YES :

Go to Step 5.

NO :

Replace the A/C compressor relay.

STEP 5. Voltage measurement at A-21X A/C
compressor relay connector.

AC510163

AE

Connector: A-21X

Relay box side

(1) Remove the relay, and measure at the relay box

side.

(2) Turn the ignition switch to the "ON" position.

AC310507

Connector A-21X
(Relay box side)

JP

(3) Voltage between terminal 1 and body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 7.

NO :

Go to Step 6.

TROUBLESHOOTING

AUTOMATIC AIR CONDITIONER

55B-52

STEP 6. Check the wiring harness between A-21X
A/C compressor relay connector terminal No.1
and the ignition switch (IG2).

AC510163

AE

Connector: A-21X

Relay box side

AC509975AS

Connector: A-28

A-28 (B)

AC509934BW

Connectors: C-207, C-210 <LHD>

Harness side

Junction block (Front view)

C-210

C-207

C-207

C-210

AC509936 BT

Connectors: C-207, C-210 <RHD>

Harness side

C-207

C-210

C-207

Junction block (Front view)

Harness side

C-210

NOTE: Prior to the wiring harness inspection, check
intermediate connector A-28, junction connector C-
207 and C-210 repair if necessary.

• Check the A/C compressor relay power supply

line for open circuit.

Q: Is the check result normal?

YES :

The trouble can be an intermittent

malfunction (Refer to GROUP 00, How to
Cope with Intermittent Malfunction ).

NO :

Repair the wiring harness.

STEP 7. Voltage measurement at A-21X A/C
compressor relay connector.

AC510163

AE

Connector: A-21X

Relay box side

(1) Remove the relay, and measure at the relay box

side.

(2) Turn the ignition switch to the "ON" position.

AC310507

Connector A-21X
(Relay box side)

JQ

(3) Voltage between terminal 4 and body earth.

OK: System voltage

Q: Is the check result normal?

YES :

Go to Step 9.

NO :

Go to Step 8.