HVAC Systems - Manual

WARNING: This page is about a different car, the 2003 Chevrolet Corvette. However, it is still accessible from the selected car via links, so may be relevant.

2. The A/C compressor relay output is disabled if engine coolant temperature is above 121°C (250°F).
3. Placing the mode switch in any position other than OFF, along with placing the air temperature control switch in a cold setting, activates A/C operation.
For the purpose of this and future steps where A/C operation is necessary, bi-level mode is used for consistent testing.
6. The HVAC control assembly is inoperative when the module does not respond to any operator control requests to enable the A/C compressor. The blower motor may still operate independent of the A/C controls.

Fig 1: Diagnostic Table (HVAC Compressor Clutch Does Not Engage) (Steps 1-5)
Courtesy of GENERAL MOTORS CORP.

Fig 2: Diagnostic Table (HVAC Compressor Clutch Does Not Engage) (Steps 6-16)

Courtesy of GENERAL MOTORS CORP.

Fig 3: Diagnostic Table (HVAC Compressor Clutch Does Not Engage) (Steps 17-29)

Courtesy of GENERAL MOTORS CORP.

Fig 4: Diagnostic Table (HVAC Compressor Clutch Does Not Engage) (Steps 30-36)

Courtesy of GENERAL MOTORS CORP.