How to Remove an Auto A/C Pressure Switch

The pressure switch in an automobile's air conditioning system disconnects the power to the system's compressor if the refrigerant pressure rises or falls out of tolerance. Out of tolerance refrigerant pressure damages the compressor's internal parts. A faulty pressure switch can prevent the compressor from turning on while the refrigerant pressures are in tolerance. An auto's A/C pressure switch attaches to a system component in the vehicle's engine compartment. The valve the vehicle's pressure switch connects to usually uses a needle valve that holds the refrigerant in the system after the pressure switch is removed.

Instructions

1

Turn off the automobile's engine.

2

Locate the pressure switch on the vehicle's air conditioning system. A high-pressure switch mounts to a fitting on the small diameter refrigerant line. A low-pressure switch either connects to a fitting on the large-diameter refrigerant line, the accumulator or a filter drier. The accumulator looks like an aluminum cylinder and mounts near the automobile's firewall. A filter drier looks like a colored, metal cylinder. Low-pressure refrigerant lines connected to a filter drier will thread into both sides of the filter drier.

3

Release the plug's locking tab and pull the plug off the pressure switch's wire terminals. Some plugs use a locking tab that releases while squeezing the plug's sides. Some plugs use a tab that releases when lifted.

4

Place the correct-sized wrench on the pressure switch near the refrigerant fitting. The wrench's jaws must fit tight against the flat spots on the pressure switch.

5

Turn the pressure switch counterclockwise with the wrench until the switch turns freely. Grip the pressure switch with one hand and unscrew the switch from the refrigerant fitting.