Your Vehicle: 2001 Ford Escort ZX2 L4-2.0L DOHC VIN 3
Vehicle » Heating and Air Conditioning » Sensors and Switches - HVAC » Refrigerant Pressure Sensor / Switch » Description and Operation » A/C Cycling Switch  
  A/C Cycling Switch  

The A/C cycling switch is mounted on a Schrader valve-type fitting on the top of the suction accumulator.

  • A valve depressor, located inside the threaded end of the A/C cycling switch, presses in on the Schrader valve stem.
  • This allows the suction pressure inside the suction accumulator to control the operation of the A/C cycling switch.
  • The electrical switch contacts open when the suction pressure drops. The contacts close when the suction pressure rises.
  • When the A/C cycling switch contacts close, the signal to energize the A/C clutch is sent to the constant control relay module.
  • When the A/C cycling switch contacts open, the A/C clutch field coil is de-energized and compressor operation stops.
  • The A/C cycling switch will control the A/C evaporator core pressure at a point where the plate/fin surface temperature will be maintained slightly above freezing.
  • This prevents icing of the A/C evaporator core and blockage of air flow.
  • It is not necessary to discharge the refrigerant system to remove the A/C cycling switch.