A/C Compressor Control Relay
WARNING: This page is about a different car, the 1999 Buick LeSabre. However, it is still accessible from the selected car via links, so may be relevant.
The A/C compressor control relay cycles the compressor clutch on and off. With ignition on, battery voltage is applied to A/C compressor control relay. The A/C compressor clutch relay is grounded by the Powertrain Control Module (PCM). When A/C or defrost mode is selected, the pressure cycling switch is closed, and relay energizes A/C compressor clutch.