A/C Cycling Switch

The A/C cycling switch senses A/C evaporator core pressure to control A/C compressor operation.

The A/C cycling switch is mounted on a Schrader valve-type fitting on the suction accumulator/driver.
- 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 or low side pressure 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 A/C clutch field coil is energized.
- 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 airflow.
- It is not necessary to perform the Refrigerant Discharging and Recovery Procedure of the refrigerant system to remove the A/C cycling switch.