The purpose of the cycling switch in a cycling clutch system is to control the evaporator temperature above the freezing point by controlling the the operation of the a/c compressor clutch. Based on pressure input from the low side of the a/c system the cycling switch will open power to the a/c compressor clutch coil when the pressure/temperature is so low that could cause the evaporator to freeze up. Once the pressure/temperature has stabilized the cycling switch closes its contacts again allowing power to the air conditioning compressor clutch coil and compressor operation is allowed until it lowers the pressure/temperature near the evaporator freezing point, where the cycle repeats again.
