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.