A/C Clutch
WARNING: This page is about a different car, the 2008 Ford RV Cutaway, 2008 Ford Econoline, and 2008 Ford Cutaway. 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) is adjusted by the PCM to compensate for additional load on the engine.