Mitsubishi Lancer Evolution IX. Manual - part 552

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-81

STEP 4. Check the wiring harness between B-13X 
A/C compressor relay connector terminal No.2 
and the ignition switch (IG2).

NOTE: 

AC504760AB

Connector: B-13X

Front of 
vehicle

1

3

2

4

Relay box side

AC504641AF

Connector: C-101, C-124 <LHD>

Harness side

C-101

C-124

C-124

C-101 (L)

AC504625AF

Connector: C-101 <RHD>

C-101 (L)

AC504618AH

Connector: C-122 <RHD>

C-122 (L)

AC504633AF

Connectors: C-210, C-211 <LHD>

Harness side

Junction block (Front view)

C-210

C-211

C-211

C-210

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-82

Prior to the wiring harness inspection, check interme-
diate connector C-124 <LH drive vehicles>, C-122 
<RH drive vehicles>, joint connector C-101, junction 
block connectors C-210 and C-211, and repair if nec-
essary.

• 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 

P.00-5

).

NO : 

Repair the wiring harness.

STEP 5. Voltage measurement at B-13X A/C 
compressor relay connector.

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

block side.

(2) Measure the 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.

AC504635AF

Harness side

C-210

Junction block (Front view)

C-211

C-211

C-210

Connectors: C-210, C-211 <RHD>

AC504760AB

Connector: B-13X

Front of 
vehicle

1

3

2

4

Relay box side

AC301541KJ

Connector B-13X 
(Relay box side)

Front of 
vehicle

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-83

STEP 6. Check the wiring harness between B-13X 
A/C compressor relay connector terminal No.1 
and the battery.

NOTE: 

Prior to the wiring harness inspection, check interme-
diate connector A-29 <LHD> or C-31 <RHD>, and 
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 

P.00-5

).

NO : 

Repair the wiring harness.

STEP 7. Connector check: A-36 A/C compressor 
connector

Q:  Is the check result normal?

YES : 

Go to Step 8.

NO : 

Repair the connector.

AC504760AB

Connector: B-13X

Front of 
vehicle

1

3

2

4

Relay box side

AC504656AC

Connector: A-29 <LHD>

A-29 (B)

AC504618AP

Connector: C-31 <RHD>

Harness side

AC504616AB

Connector: A-36

A-36 (B)

Harness side

TROUBLESHOOTING

HEATER, AIR CONDITIONER AND VENTILATION

55-84

STEP 8. Check the wiring harness between B-13X 
A/C compressor relay connector terminal No.4 
and A-36 A/C compressor connector terminal 
No.1.

NOTE: 

Prior to the wiring harness inspection, check interme-
diate connector A-13 <LHD> or C-31 <RHD>, and 
repair if necessary.

• Check the A/C compressor power supply line for 

open circuit.

Q: Is the check result normal?

YES : 

Go to Step 9.

NO : 

Repair the wiring harness.

STEP 9. Connector check: C-121 engine-ECU 
connector

Q:  Is the check result normal?

YES : 

Go to Step 11.

NO : 

Repair the connector.

AC504616AB

Connector: A-36

A-36 (B)

Harness side

AC504760AB

Connector: B-13X

Front of 
vehicle

1

3

2

4

Relay box side

AC504656AD

Connector: A-13 <LHD>

A-13 (B)

AC504618AP

Connector: C-31 <RHD>

Harness side

AC504617AB

Connector: C-121 <LHD>

C-121 (GR)

Harness side

AC504618AB

Connector: C-121 <RHD>

Harness side

C-121 (GR)