Test C: The Air Conditioning (A/C) Is Inoperative/Does Not Operate Correctly

PINPOINT TEST C: THE AIR CONDITIONING (A/C) IS INOPERATIVE/DOES NOT OPERATE CORRECTLY

C1-C3:

C4-C7:

C7-C9:

C10-C11:

C12-C13:

C13-C15:

C15 Continued:

C16-C18:

C18 Continued:

C19-C20:

C20 Continued:

Normal Operation
Under normal operation, voltage is provided to the function selector switch through circuit 498 (PK/BK). When A/C is requested, a voltage is sent from the function selector switch to the A/C cycling switch through circuit 348 (VT). Voltage is sent from the A/C cycling switch to the (diesel engine) dual-function pressure switch, (gasoline engine) A/C high pressure switch through circuit 441 (RD/YE). Voltage is sent from the (diesel engine) dual-function pressure switch (gasoline engine) A/C high pressure switch to the powertrain control module (PCM) through circuit 347 (BK/YE).

The PCM provides a ground for the A/C clutch relay coil through circuit 331 (PK/YE). The A/C clutch relay coil receives ignition voltage through circuit 361 (RD). Battery voltage for the A/C clutch relay switch is provided through circuit 932 (GY/WH). When the relay is energized, voltage is supplied to the A/C clutch solenoid through circuit 321 (GY/WH). Ground is supplied for the A/C clutch through circuit 57 (BK).

Possible Causes
- Fuse(s)
- An open in circuits 57 (BK), 321 (GY/WH), 331 (PK/YE), 347 (BK/YE), 348 (VT), 361 (RD), 441 (RD/YE), 498 (PK/BK) or 932 (GY/WH)
- PCM
- Function selector switch
- A/C cycling switch
- Dual-function pressure switch
- A/C high pressure switch
- A/C compressor clutch field coil
- A/C control relay
- A/C clutch air gap