Evaporator Temperature Sensor / Switch: Description and Operation

The evaporator probe can be replaced without having to remove the A/C housing from the vehicle.

The evaporator probe is located in the A/C housing and placed in the evaporator fins. The probe prevents evaporator freeze-up. This is done by cycling the compressor clutch OFF when evaporator temperature drops below the freeze point. It cycles ON when the evaporator temperature rises above the freeze point. The evaporator probe uses a thermistor probe in a capillary tube. The tube is inserted between the evaporator fins in the heater-A/C housing.