2001 Chevrolet Silverado 1500 - A/C Pressure Switch

An air conditioning (A/C) pressure switch monitors the pressure inside the air conditioning system to ensure proper refrigerant flow. If refrigerant levels are low, or if other issues in the A/C system prevent it from reaching appropriate operating pressure, the A/C pressure switch will deactivate the compressor clutch. This prevents the compressor from cycling and limits the risk of compressor damage due to low refrigerant or oil levels.