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Compressor Clutch Relay: Description and Operation

A/C Control Circuit Diagram:





The PCM controls the A/C compressor clutch through a relay. When the A/C is turned "ON" and there are no system malfunctions (such as low refrigerant pressure), the PCM energizes the compressor clutch relay by completing the relay coil circuit to ground. This connects power to the compressor clutch, engaging it.