Operation CHARM: Car repair manuals for everyone.

Compressor Clutch Does Not Engage

TEST DESCRIPTION

Steps 1-6:




Steps 7-17:




Steps 18-29:




Steps 30-39:




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. There are two A/C request outputs from the HVAC control assembly. One request comes from the mode switch when in defrost or recirculation mode and the other request comes from the A/C switch. If there is an open in the A/C request circuit before the splice, the A/C may operate from the mode switch, but not from the A/C switch or vice versa.
8. The HVAC control assembly is inoperative when the HVAC control unit does not respond to any operator control request to enable the A/C compressor. The blower motor may still operate independent of the A/C controls.
19. Be sure to check both of the request circuits before the splice.