Expedition 4WD V8-4.6L SOHC VIN W (1999)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/C Pressure Cutoff Switch
Typical Air Conditioning Pressure Sensor
The A/C pressure cut-off 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 cut-off 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 cut-off switch, presses on the Schrader valve stem.
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This allows the A/C pressure cut-off 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 recover the refrigerant system to remove the A/C pressure cut-off switch.
