GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Prizm 🢒 HVAC 🢒 HVAC Systems - Manual 🢒 HVAC Compressor Clutch Does Not Engage
Table 1: Compressor Control Module Voltage Table

Step

Action

Yes

No

1

Did you perform the HVAC System Check?

Go to Step 2

Go to HVAC System Check

2
  1. Disconnect the A/C compressor clutch connector.
  2. Connect a test lamp across the connector.
  3. Start the engine.
  4. Press the A/C switch to the ON position.
  5. Turn the blower speed selector switch to any position except OFF.

Does the test lamp light?

Go to Step 3

Go to Step 4

3

Replace the A/C compressor clutch. Refer to Compressor Clutch Coil Removal (V5 - Direct Mount) and Compressor Clutch Coil Install (V5 - Direct Mount) .

Is the repair complete?

Go to HVAC System Check

--

4

Test for an open in the WHT/BLK wire between the A/C compressor clutch and G103 (including fuse and relay block 1).

Is an open present?

Go to Step 27

Go to Step 5

5

Test for an open between the A/C MG relay in fuse and relay block 2 and the A/C compressor clutch (BLK/WHT wire, fuse and relay block 1, BLU/YEL wire).

Is an open present?

Go to Step 27

Go to Step 6

6
  1. Connect the A/C compressor clutch connector.
  2. Remove the A/C MG relay from fuse and relay block 2.
  3. Start the engine and turn the blower speed selector switch to any position except OFF.
  4. Test for battery voltage between the A/C MG relay cavity 5 and ground. Refer to

    Fuse and Relay Block 2
    Object Number: 334466 Size: SF
    (1)A/C MG Relay
    (2)A/C FAN No.3 Relay
    (3)A/C FAN No.3 Relay
    (4)Dimmer Relay
    (5)CDS Fuse 30A
    (6)HEAD (LH-LWR) Fuse 10A
    (7)HEAD (RH-LWR) Fuse 10A
    (8)DRL Fuse 7.5A
    (9)Fuse and Relay Block 2
    in Wiring Systems.
  5. Test for battery voltage between the A/C MG relay cavity 1 and ground. Refer to

    Fuse and Relay Block 2
    Object Number: 334466 Size: SF
    (1)A/C MG Relay
    (2)A/C FAN No.3 Relay
    (3)A/C FAN No.3 Relay
    (4)Dimmer Relay
    (5)CDS Fuse 30A
    (6)HEAD (LH-LWR) Fuse 10A
    (7)HEAD (RH-LWR) Fuse 10A
    (8)DRL Fuse 7.5A
    (9)Fuse and Relay Block 2
    in Wiring Systems.

Is battery voltage present in both cases?

Go to Step 8

Go to Step 7

7

Repair the open in the BLU/RED wire between the A/C MG relay terminal 5 and fuse and relay block 3 OR in the BLU/RED wire between the A/C MG relay connector terminals 1 and 5.

Is the repair complete?

Go to HVAC System Check

--

8
  1. Turn the ignition switch to the LOCK position.
  2. Install the A/C MG relay.
  3. Start the engine.
  4. Test for battery voltage between the A/C compressor control module connector terminal 1 and ground.

Is battery voltage present?

Go to Step 10

Go to Step 9

9

Test for an open between the A/C compressor control module connector terminal 1 and fuse and relay block 2 (including the A/C refrigerant pressure switch).

Is an open present?

Go to Step 27

Go to Step 28

10

Test for a short to ground in the BLU/WHT wire between the underhood data link connector terminal 8 (TE 1) and the PCM connector 2 terminal 15. Grounding this circuit puts the vehicle in diagnostic request mode and will prevent the A/C from operating when the engine speed is below 1200 RPM.

Is a short to ground present?

Go to Step 27

Go to Step 11

11
  1. Turn the ignition switch to the LOCK position.
  2. Install the A/C MG relay.
  3. Disconnect the A/C compressor control module connector.
  4. Connect a fused jumper from the A/C compressor control module connector terminal 9 to ground.
  5. Start the engine.
  6. Depress the A/C switch to the ON position.
  7. Turn the blower speed selector switch to any position except OFF.

Does the A/C compressor clutch engage?

Go to Step 14

Go to Step 12

12

Test for an open in the BLU/BLK wire between the A/C MG relay and the A/C compressor control module.

Is an open present?

Go to Step 27

Go to Step 13

13

Replace the A/C MG relay. Refer to Condenser Fan Relay Replacement .

Is the repair complete?

Go to HVAC System Check

--

14

Test for an open in WHT/BLK wire between the A/C compressor control module connector terminal 4 and G203.

Is an open present?

Go to Step 27

Go to Step 15

15

Test for battery voltage at terminal 5 of the A/C compressor control module connector.

Is battery voltage present?

Go to Step 20

Go to Step 16

16

Test for battery voltage at terminal 6 of the A/C switch connector.

Is battery voltage present?

Go to Step 17

Go to Step 19

17

Test for an open in the YEL wire between the A/C switch and the A/C compressor control module.

Is an open present?

Go to Step 27

Go to Step 18

18

Replace the A/C switch. Refer to Control Assembly Replacement .

Is the repair complete?

Go to HVAC System Check

--

19

Repair the open in the BLU/RED wire between the A/C switch and fuse and relay block 3. Refer to Wiring Repairs in Wiring Repairs.

Is the repair complete?

Go to HVAC System Check

--

20
  1. Turn the ignition switch to the LOCK position.
  2. Connect the A/C compressor control module connector.
  3. Depress the A/C switch to the OFF position.
  4. Turn the ignition switch to the ON position.
  5. Test for battery voltage between the A/C compressor control module connector terminal 8 and ground.

Is battery voltage present?

Go to Step 21

Go to Step 24

21
  1. Start the engine.
  2. Depress the A/C switch to the ON position.
  3. Measure the voltage between the A/C compressor control module connector terminal 8 and ground.

Is the voltage 0-1 volt?

Go to Step 22

Go to Step 26

22
  1. Turn the ignition switch to the ON position.
  2. Depress the A/C switch to the OFF position.
  3. Measure the voltage between the A/C compressor control module connector terminal 3 and ground.

Is the voltage 0-1 volt?

Go to Step 23

Go to Step 25

23
  1. Start the engine.
  2. Depress the A/C switch to the ON position.
  3. Test for battery voltage between the A/C compressor control module connector terminal 3 and ground.

Is battery voltage present?

Go to Step 26

Go to Step 25

24

Test for an open or a short to ground in YEL/RED wire between the PCM and the A/C compressor control module.

Was an open or short found?

Go to Step 27

Go to Air Conditioning (A/C) Idle Circuit Diagnosis in Engine Controls

25

Test for a short to ground in RED/BLU wire between the PCM and the A/C compressor control module.

Was a short found?

Go to Step 27

Go to Air Conditioning (A/C) Idle Circuit Diagnosis in Engine Controls

26

Replace the A/C compressor control module. Refer to Air Conditioning (A/C) Compressor Control Module Replacement .

Is the repair complete?

Go to HVAC System Check

--

27

Repair the open/short. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to HVAC System Check

--

28

Replace the A/C refrigerant pressure switch. Refer to A/C Refrigerant Pressure Sensor Replacement .

Is the repair complete?

Go to HVAC System Check

--

Compressor Control Module Voltage Table

Terminal

Circuit

Normal Voltage

Condition

1

Refrigerant Pressure Switch

B+

Ignition switch ON

2

Not Used

3

A/C Cutout Signal (WOT)

0-1 Volt

Ignition Switch ON, A/C Switch OFF

10-14 Volts

Engine Running, A/C Operating

4

Ground

0-1 Volt

Ignition switch ON

5

Ignition Positive Voltage

B+

Ignition Switch ON, A/C Switch ON or Defrost Switch ON

6-7

Not Used

8

A/C ON Output Control

10-14 Volts

Ignition Switch ON, A/C Switch OFF

0-1 Volt

Engine Running, A/C Operating

9

A/C MG Relay Control

B+

Ignition Switch ON, A/C Switch OFF

0-1.5 Volts

Engine Running, A/C Operating

10

Not Used