A/C Clutch Circuit Diagnosis

Operation of the A/C compressor clutch is dependent on the ambient temperature and signals from the engine computer. The system is designed to interrupt A/C compressor operation when certain conditions exist. The A/C compressor clutch can be shut off (or kept off) for several seconds at engine start-up, at high engine speeds, during acceleration, when the engine coolant temperature exceeds a predetermined temperature and during low engine idle conditions (app. 200 rpm below low idle specs.) Refer to the following diagnostic procedures and, if necessary, the Powertrain Control Emissions Diagnosis Manual to identify an inoperative compressor clutch condition. The ambient temperature must also be above approximately 50°F for A/C compressor operation.