Navigator 4WD V8-5.4L DOHC VIN A (2000)
Air Conditioning High Pressure Switch
Typical Air Conditioning Pressure Sensor
Air Conditioning High Pressure Switch
The A/C high pressure switch is used for additional A/C system pressure control. The A/C high pressure switch is either dual function for two-speed
electric fan applications or single function for all others.
For refrigerant containment control, the normally closed high pressure contacts open at a predetermined A/C pressure. This will result 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 will then turn on the high speed fan to help reduce the pressure.
The A/C pressure cutoff switch is used to interrupt A/C compressor operation in the event of high system discharge pressures.
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The A/C pressure cutoff switch is mounted on a Schrader valve-type fitting on the high pressure side of the A/C manifold and tube.
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A valve depressor, located inside the threaded end of the A/C pressure cutoff switch, presses on the Schrader valve stem.
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This allows the A/C pressure cutoff switch to monitor the compressor discharge pressure.
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When the compressor discharge pressure rises to approximately 2,896 kPa (420 psi), the switch contacts open, disengaging the A/C compressor.
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When the pressure drops to approximately 1724 kPa (250 psi) the contacts close to allow operation of the A/C compressor.
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It is not necessary to discharge the refrigerant system to remove the A/C pressure cutoff switch.
For additional information, refer to the Wiring Diagrams.
