Mitsubishi L200. Manual - part 850

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-16

STEP 19. Check the wiring harness between A-38 
dual pressure switch connector terminal No.1 
and C-105 engine-ECU connector terminal No.15.

AC509977AG

Harness side

A-38 (BR)

Connector: A-38

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

NOTE: 

AC509975AH

Connector: A-28

A-28 (B)

Prior to the wiring harness inspection, check interme-
diate connector A-28, and repair if necessary.

• Check the dual pressure switch signal line.

Q: Is the check result normal?

YES : 

Go to Step 20.

NO : 

Repair the wiring harness.

STEP 20. Check the A/C compressor clutch 
operation.
 Refer to 

P.55A-81

.

Q: Can the sound of the A/C compressor clutch (click) 

be heard?
YES : 

Go to Step 21.

NO : 

Replace the A/C compressor clutch. 

STEP 21. Refrigerant level check
Check that the refrigerant level is adequate. Refer to 

P.55A-63

.

Q: Is the check result normal?

YES : 

Go to Step 22.

NO : 

Charge or remove the refrigerant level. 
Refer to 

P.55A-63

.

STEP 22. Replace the A/C switch module, and 
then recheck the trouble symptom
 Check that the cooler works normally.

Q: Is the check result normal?

YES : 

This diagnosis is complete.

NO : 

Go to Step 23.

STEP 23. Replace the A/C evaporator air outlet 
thermistor, and then recheck the trouble 
symptom
 Check that the cooler works normally.

Q: Is the check result normal?

YES : 

This diagnosis is complete.

NO : 

Replace the engine-ECU.

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-17

Inspection Procedure 2: The blower does not work

Blower Motor Circuit

BLOWER
SWITCH

A/C TEMPERATURE
CONTROL RESISTOR

BLOWER
MOTOR

FUSIBLE
LINK

IGNITION
SWITCH (IG2)

BLOWER
RELAY

20

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

Blower Motor Circuit

BLOWER
SWITCH

A/C TEMPERATURE
CONTROL RESISTOR

BLOWER
MOTOR

FUSIBLE
LINK

IGNITION
SWITCH (IG2)

BLOWER
RELAY

20

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

AC900880

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-18

COMMENTS ON TROUBLE SYMPTOM
If the blower motor does not operate, the blower 
motor circuit system may be defective.

PROBABLE CAUSES

• Malfunction of the blower relay

• Malfunction of the blower motor

• Malfunction of the blower switch

• Damaged the wiring harness or connectors

DIAGNOSIS PROCEDURE

STEP 1. Check that the blower motor operates 
when the blower switch is moved to the "4 (HI) " 
position.
(1) Turn the ignition switch to the "ON" position.
(2) Turn the blower switch to the "4 (HI) " position.

Q: Does the blower motor operate when the blower 

switch is moved to the "4 (HI) " position?
YES : 

Refer to Inspection procedure 3 "The blower 

air volume cannot be changed 

P.55A-26

."

NO : 

Go to Step 2.

STEP 2. Connector check: C-28 blower motor 
connector

AC509613AS

Harness side

Connector: C-28 <LHD>

AC509930AR

Harness side

Connector: C-28 <RHD>

Q: Is the check result normal?

YES : 

Go to Step 3.

NO : 

Repair the connector.

STEP 3. Resistance measurement at the C-28 
blower motor connector.

AC509613AS

Harness side

Connector: C-28 <LHD>

AC509930AR

Harness side

Connector: C-28 <RHD>

(1) Disconnect the connector, and measure at the 

wiring harness side.

AC403234

Connector C-28 
(Harness side)

CF

(2) Measure the resistance between terminal 2 and 

body earth.

OK: Continuity (Less than 2

Ω)

Q: Is the check result normal?

YES : 

 Go to Step 5.

NO : 

Go to Step 4.

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55A-19

STEP 4. Check the wiring harness between C-28 
blower motor connector terminal No.2 and body 
earth.

AC509613AS

Harness side

Connector: C-28 <LHD>

AC509930AR

Harness side

Connector: C-28 <RHD>

• Check the blower motor earth line for open cir-

cuit.

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 5. Voltage measurement at C-28 blower 
motor connector.

AC509613AS

Harness side

Connector: C-28 <LHD>

AC509930AR

Harness side

Connector: C-28 <RHD>

(1) Disconnect the connector, and measure at the 

wiring harness side.

(2) Turn the ignition switch to the "ON" position.
(3) Turn the blower switch to the "4 (HI) " position.

AC402679

Connector C-28 
(Harness side)

CG

(4) Measure the voltage between terminal 1 and 

body earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 18.

NO : 

Go to Step 6.