Operation CHARM: Car repair manuals for everyone.

Control Module HVAC: Description and Operation

Compressor Control System Description




The compressor control unit has a system designed to protect the compressor belt in the event of a seizure, thereby allowing the alternator to continue operating.

This is done by comparing the engine rpm and the compressor pulley rpm. When there is a difference in rpm that continues for more than 3 seconds, the compressor relays are turned off and the warning light comes on.

To reset, push the A/C switch off, then push it on again.

NOTE: If the switch is pushed off and on more than twice, it will be necessary to turn off the ignition to reset.