Air Conditioning (A/C) High Pressure Switch

Air Conditioning (A/C) High Pressure Switch
The A/C high pressure switch is used for additional A/C system pressure control. For refrigerant containment control, the normally closed high pressure contacts open at a predetermined A/C pressure. This results in the A/C turning off, preventing the A/C pressure from rising to a level that would open the 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 the PCM. The PCM then turns on the high speed fan to help reduce the pressure.

For additional information, refer to Heating and Air Conditioning, Climate Control.

Air Conditioning (A/C) Low Pressure Switch
The A/C low pressure switch is used for additional A/C system pressure control. This normally closed switch opens when the refrigerant pressure drops below 152 kPa (22 psi). This results in the A/C turning off, preventing the evaporator from freezing.