Pressure Cycling Switch
WARNING: This page does not describe the selected car, but rather 38 other vehicles, including the 1987 Pontiac Sunbird, 1987 Pontiac Safari, 1987 Pontiac Grand Prix, 1987 Pontiac Grand Am, and 1987 Pontiac Firebird. However, it is still accessible from the selected car via links, so may be relevant.
Located near the top of the accumulator, this switch cycles the compressor on at 46 psi and off at 25 psi. Switch also turns off compressor in event of low refrigerant charge or cold (below 37°F) ambient temperatures.