Air Conditioning (A/C) Clutch
WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The A/C cycling switch is located on the suction accumulator/drier of an original equipment manufacture (OEM) factory-installed air conditioning system. When the air conditioning clutch cycling switch contacts close, the PCM receives a signal voltage from the A/C clutch switch indicating that the A/C compressor clutch is engaged. The PCM uses the A/C clutch cycling switch signal to adjust line pressure to compensate for the additional engine load.