Compressor Clutch Does Not Engage

HVAC Compressor Clutch Does Not Engage

Test Description

Step 1 - Step 6:

Step 7 - Step 16:

Step 17 - Step 30:

Step 31 - Step 34:

The numbers below refer to the step numbers on the diagnostic table.
2. The A/C compressor relay output is disabled if engine coolant temperature is above 124°C (255°F).
3. Placing the fan switch in the ON position, 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 module 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.