Air Conditioning (A/C) Clutch

WARNING: This page is about a different car, the 2004 Ford Pickup, 2004 Ford F550 Super Duty, 2004 Ford F450 Super Duty, 2004 Ford Excursion, and 2004 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

An electromagnetic clutch is energized when the clutch cycling pressure switch closes.
The switch is located on the suction accumulator/drier.
The closing of the switch completes the circuit to the clutch and draws it into engagement with the compressor driveshaft.
When the A/C clutch is engaged, electronic pressure control (EPC) pressure is adjusted by the PCM to compensate for additional load on the engine.