Mark LT 2WD V8-5.4L VIN 5 (2007)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/C Cycling Switch
AIR CONDITIONING (A/C) CYCLING SWITCH
The A/C cycling switch is mounted on a Schrader valve-type fitting on the suction accumulator.
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A valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the Schrader valve stem.
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This allows the suction pressure to control the operation of the A/C cycling switch.
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The electrical switch contacts open when the suction pressure drops. The contacts close when the suction pressure rises.
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When the A/C cycling switch contacts close, the signal to energize the A/C compressor clutch field coil is sent to the PCM.
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When the A/C cycling switch contacts open, the A/C compressor clutch field coil is de-energized and A/C compressor operation stops via the
PCM and A/C clutch relay.
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The A/C cycling switch will control the evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly
above freezing.
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This prevents icing of the evaporator core and blockage of airflow.
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It is not necessary to recover the refrigerant to remove the A/C cycling switch.