A/C High Pressure Switch

The A/C high pressure switch is used for additional A/C system pressure control. A/C high pressure switch is either dual function for 2-speed fan control applications or single function for all other applications. For refrigerant containment control, the normally closed high pressure contacts open at a predetermined A/C pressure. This will result in A/C turning off, preventing A/C pressure from rising to a level that would open A/C high pressure relief valve. For fan control, the normally open medium pressure contacts close at a predetermined A/C pressure. This grounds the ACPSW circuit input to Powertrain Control Module (PCM). The PCM will then turn on the high speed fan to help reduce A/C pressure.