Mitsubishi Galant. Manual — part 722

MANUAL A/C DIAGNOSIS

TSB Revision

HEATING AND AIR CONDITIONING

55-14

STEP 2. Check the blower relay continuity.

Q: Is the blower relay continuity in good condition?

YES : Go to Step 3.
NO : Replace. Then go to Step 4.

STEP 3. Check the blower switch continuity.

Q: Is the blower switch continuity in good condition?

YES : Go to Step 4.
NO : Replace. Then go to Step 4.

STEP 4. Check symptoms.

Q: Does the blower motor stop turning?

YES : This diagnosis is complete. (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to Introduction, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction

P.00-8

.)

NO : Go to Step 1.

BATTERY
VOLTAGE

TERMINAL NO.
TO BE
CONNECTED TO
BATTERY

TERMINAL NO.
TO BE
CONDUCTED

SUPPLIED

1-3

2-5

NOT SUPPLIED

-

1-3

AC003706 AB

BLOWER RELAY

SWITCH
POSITION

TESTER
CONNECTION
(CONNECTOR A)

SPECIFIED
CONDITION

0 (OFF)

-

No continuity

1 (LO)

3-5

Continuity

2 (ML)

1-3

Continuity

3 (MH)

3-6

Continuity

4 (HI)

3-4

Continuity

AC001381AB

BLOWER SWITCH
ASSEMBLY

MANUAL A/C DIAGNOSIS

TSB Revision

HEATING AND AIR CONDITIONING

55-15

INSPACTION PROCEDURE 6: WHEN THE A/C IS OPERATING CONDENSER FAN OR RADIATOR FAN
DOES NOT TURN.

DIAGNOSIS

STEP 1. Check the fan control relay continuity.

Q: Is the fan control relay continuity in good condition?

YES : Go to Step 2.
NO : Replace. Then go to Step 4.

STEP 2. Check the condenser fan motor operation
<vehicles with 3.0L engine>.
Check to be sure that the condenser fan motor operates when
battery voltage is applied to terminal 2 and terminal 1
grounded.

Q: Is the condenser fan motor operating correctly?

YES : Go to Step 3.
NO : Replace. Then go to Step 3.

STEP 3. Measure the fan controller terminal voltage.
Refer to GROUP 14, On-vehicle Service

−

Fan Control Module

Check

P.14-15

Q: Is the fan controller terminal voltage in good condition?

YES : Go to Step 4.
NO : Replace. Then go to Step 4.

BATTERY
VOLTAGE

TERMINAL NO.
TO BE
CONNECTED TO
BATTERY

TERMINAL NO.
TO BE
CONDUCTED

SUPPLIED

1-3

2-5

NOT SUPPLIED

-

1-3

AC001382

FAN CONTROL RELAY

AB

AC001383AB

MANUAL A/C DIAGNOSIS

TSB Revision

HEATING AND AIR CONDITIONING

55-16

STEP 4. Check symptoms.

NOTE: Condenser fan might not operate when there is an air
conditioning low load from the air conditioning condenser
control, so remove the negative battery terminal and then
check the symptoms after 5 minutes since initial start control
after reconnection.

Q: Is the condenser fan or radiator fan operating correctly?

YES : This diagnosis is complete. (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to Introduction, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction

P.00-8

.)

NO : Go to Step 1.

INSPACTION PROCEDURE 7: THE A/C INDICATOR FLASHES <VEHICLES WITH 3.0L ENGINE> .

THE A/C INDICATOR FLASHES.

STEP 1. Check the drive belt tension.
Refer to GROUP 00, Lubrication and Maintenance Service

−

Drive belts.

Q: Is the drive belt tension in good condition?

YES : Go to Step 2.
NO : Repair. Then go to Step 4.

STEP 2. Check the revolution pick-up sensor.
Measure the resistance between terminals 1 and 3. Check that
the measured value is at the standard value.

Standard value: 405

±±±±

35 when the ambient

temperature is 20

°°°°

C (68

°°°°

F

))))

Q: Is the measured value at the standard value?

YES : Go to Step 3.
NO : Replace. Then go to Step 3.

AC003633

1 2

3 4

AB

REVOLUTION
PICK-UP SENSOR

MANUAL A/C DIAGNOSIS

TSB Revision

HEATING AND AIR CONDITIONING

55-17

STEP 3. Check the harness wire between the compressor
connector B-45 and automatic compressor controller
connector C-16.
Q: Is the harness wire between the compressor connector

B-45 and automatic compressor controller connector C-
16 in good condition?
YES : Go to Step 4.
NO : Repair. Then go to Step 4.

STEP 4. Measure the automatic compressor controller
terminal voltage.
Refer to

P.55-17

.

Q: Is the automatic compressor controller terminal voltage

in good condition?
YES : Go to Step 5.
NO : Replace. Then go to Step 5.

STEP 5. Check symptoms.

Q: Does the A/C indicator flashes?

YES : Go to Step 1.
NO : This diagnosis is complete. (If no malfunctions are not

found in all steps, an intermittent malfunction is
suspected. Refer to GROUP 00E, How to Use
Troubleshooting/Inspection Service Points

−

How to

Cope with Intermittent Malfunction

P.00-8

.)

CHECK AT ECU TERMINAL

M1552010300088

AC003737

CONNECTOR: B-45

AB

AC003733

CONNECTOR: C-16

AC

1

2 3 4 5 6

7 8

9 10

11 12 13 14 15 16 17 18 19 20

21 22 23 24

25 26 27 28

AC002292AB