A/C Cycling Switch
WARNING: This page is about a different car, the 2007 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
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. For specifications regarding operating pressure(s), refer to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS article.
- When the A/C cycling switch contacts close, the signal to energize the A/C compressor clutch field coil is sent to the powertrain control module (PCM). The PCM will then actuate the A/C control relay, energizing the A/C compressor.
- When the A/C cycling switch contacts open, the A/C compressor clutch field coil is de-energized and A/C compressor operation stops.
- 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.
- This prevents icing of the evaporator core and blockage of airflow.
- It is not necessary to discharge the refrigerant system to remove the A/C cycling switch.