Mitsubishi Galant (2004+). Manual - part 782

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-267

ADJUSTMENT

1. Select a quiet area for testing. Duplicate 

conditions as much as possible. Switch the 
compressor on and off several times to clearly 
identify compressor noise. To duplicate high 
ambient conditions (high head pressure), restrict 
air flow through the condenser. Install a manifold 
gauge set to make sure discharge pressure 
doesn't exceed 2,070 kPa (300.2 psi).

2. Tighten all compressor mounting bolts, clutch 

mounting bolt, and compressor drive belt. Check 
to assure clutch coil is tight (no rotation or 
wobble).

3. Check refrigerant hoses for rubbing or 

interference that can cause unusual noises.

4. Check refrigerant charge. (Refer to 

P.55A-264

).

5. Recheck compressor noise as in Step 1.
6. If noise still exists, loosen compressor mounting 

bolts and retighten. Repeat Step 1.

7. If noise continues, replace compressor and repeat 

from Step 1.

POWER RELAY CHECK

M1552008800321

BLOWER RELAY CONTINUITY CHECK

BATTERY 
VOLTAGE

TESTER 
CONNECTION

SPECIFIED 
CONDITION

Not applied

4 

− 5

Open circuit

• Connect 

terminal 1 to the 
positive battery 
terminal

• Connect 

terminal 3 to the 
negative battery 
terminal

4 

− 5

Less than 2 ohms

AC306657

AB

4

5

1 2 3

5

1

4

3

BLOWER RELAY

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-268

A/C COMPRESSOR CLUTCH RELAY CONTINUITY 
CHECK

FAN CONTROL RELAY CONTINUITY CHECK

BATTERY 
VOLTAGE

TESTER 
CONNECTION

SPECIFIED 
CONDITION

Not applied

1 

− 4

Open circuit

• Connect 

terminal 2 to the 
positive battery 
terminal

• Connect 

terminal 3 to the 
negative battery 
terminal

1 

− 4

Less than 2 ohms

AC306655

2

1

3

4

1

2

4

3

AB

A/C COMPRESSOR CLUTCH RELAY

FRONT OF 
VEHICLE

JUNCTION BLOCK 
TRIANGLE MARK

BATTERY 
VOLTAGE

TESTER 
CONNECTION

SPECIFIED 
CONDITION

Not applied

3 

− 4

Open circuit

• Connect 

terminal 2 to the 
positive battery 
terminal

• Connect 

terminal 1 to the 
negative battery 
terminal

3 

− 4

Less than 2 ohms

AC306658

FAN CONTROL RELAY

AB

4

1

2

3

3

1

4

2

ON-VEHICLE SERVICE

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-269

IDLE-UP OPERATION CHECK

M1552001600401

<2.4 L engine>

1. Before inspection and adjustment, set vehicle in the 

following condition:

• Engine coolant temperature: 80 − 90 °C (176.0 − 194.0 °F)

• Lights, electric cooling fan and accessories: OFF

• Transmission: Neutral ("N" or "P" position)

• Steering wheel: Straightforward

2. Check whether or not the idle speed is the standard value. 

Refer to GROUP 11A, On-vehicle Service 

− Idle Speed 

Check 

P.11A-13

.

Standard value: 700 

± 50 r/min

3. Turn on the air conditioning switch and the blower speed 

selection dial. Engine idling speed should be within the 
standard value:

Standard value: 700 

± 50 r/min

NOTE: It is not necessary to make an adjustment, because 
the idling speed is automatically adjusted by the ISC sys-
tem. If, however, a deviation from the standard value occurs 
for some reason, check the ISC system. (Refer to GROUP 
11A, On-vehicle Service 

−

 Idle Speed Check 

P.11A-13

)

<3.8 L engine>

1. Before inspection and adjustment, set vehicle in the 

following condition:

• Engine coolant temperature: 80 − 90 °C (176.0 − 194.0 °F)

• Lights, electric cooling fan and accessories: OFF

• Transmission: Neutral ("N" or "P" position)

• Steering wheel: Straightforward

2. Check whether or not the idle speed is the standard value. 

Refer to GROUP 11C, On-vehicle Service 

− Idle Speed 

Check 

P.11C-9

.

Standard value: 680 

± 50 r/min

3. Turn on the air conditioning switch and the blower speed 

selection dial. Engine idling speed should be within the 
standard value:

Standard value: 680 

± 50 r/min

NOTE: The powertrain control module determines whether 
the A/C load is low or high according to the output signal 
from the A/C-ECU.
NOTE: It is not necessary to make an adjustment, because 
the idling speed is automatically adjusted by the ISC sys-
tem. If, however, a deviation from the standard value occurs 
for some reason, check the ISC system. (Refer to GROUP 
11C, On-vehicle Service 

−

 Idle Speed Check 

P.11C-9

)

HEATER CONTROL ASSEMBLY AND A/C SWITCH

TSB Revision

HEATER, AIR CONDITIONING AND VENTILATION

55A-270

HEATER CONTROL ASSEMBLY AND A/C SWITCH

REMOVAL AND INSTALLATION

M1552002400369

INSPECTION

M1552014301146

BLOWER SWITCH CONTINUITY CHECK 

AC306519

1

2

3

AB

<LOW TYPE>

AC306801

1

2

3

AB

<LOW TYPE>

REMOVAL STEPS

1.

CENTER PANEL ASSEMBLY 
(REFER TO GROUP 52A, 
INSTRUMENT PANEL 

P.52A-3

)

2.

KNOB

3.

HEATER CONTROL (A/C-ECU)

REMOVAL STEPS (Continued)

SWITCH 
POSITION

TESTER CONNECTION 
(CONNECTOR A) 

SPECIFIED 
CONDITION

0 (OFF)

1 

− 4, 2− 4, 4 − 5, 4 − 6

Open circuit

1 (LO)

1 

− 4

Less than 2 ohms

2 (ML)

4 

− 6

Less than 2 ohms

3 (MH)

2 

− 4

Less than 2 ohms

4 (HI)

4 

− 5

Less than 2 ohms

AC306526

1
3 4 5 6

2