help!!! 86 vette with auto climate control.:confused: compressor clutch not operating. Have checked clutch operates when hot wired, but does not operate when cooling is called for from front end controller. all other functions operate as in blower fan starts, engine revs increase but compressor clutch does not initiate??? any clues to this problem???:confused:

Could it be low on freon?

Have checked refrigerant charge ok. It appears a/c clutch is not being grounded