A/C Pressure Cutoff Switch

An A/C pressure cut-off switch is used on all vehicles to interrupt operation of the A/C compressor in the event of high system discharge pressures.

The A/C pressure cut-off switch is located in the discharge line between the A/C compressor and the A/C condenser core.

Dual Function
The A/C pressure cut-off switch has two sets of contacts. One electrical contact is normally closed.
^ When compressor head pressure rises to 2860-3068 kPa (415-445 psi), the contacts open and the compressor operation is shut off.
^ When head pressure drops to 1517-1930 kPa (220-280 psi), the contacts again close and allow operation of the A/C compressor.
^ Shutting down compressor operation prior to the pressure relief valve set point 3103 kPa (450 psi) makes sure refrigerant is contained in the A/C system.

The switch contains a second set of electrical contacts used for high-speed fan control which are normally open.
^ When discharge line pressure reaches 1965-2172 kPa (285-315 psi), these contacts close and engage the high-speed fan control.
^ When pressure drops to approximately 1896 kPa (275 psi), the contacts again open and the high-speed fan control is disengaged.