Compressor Clutch Does Not Engage

HVAC COMPRESSOR CLUTCH DOES NOT ENGAGE

TEST DESCRIPTION

Steps 1 - 8:

Steps 9 - 20:

Steps 21 - 34:

Steps 35 - 39:

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 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.
5. The HVAC control assembly is inoperative when the assembly does not respond to any operator control requests.
24. Ensure to test both A/C request signal circuits of the A/C high pressure sensor for the listed conditions.