Evaporator Temperature Sensor / Switch: Testing and Inspection

THERMOSTATIC SWITCH (THERMISTOR)

SENSOR CHECKING




The thermistor will detect the core temperature and interrupt compressor relay power, in order to prevent evaporator freezing by excessive cooling.

The thermistor is an NTC device.

THERMISTOR CHECK

1. Remove the glove box.
2. Start the engine.
3. Turn on the air conditioner.




4. With the thermostatic switch connector in coupled state, install a voltmeter between 1 and 2 (-) terminal and check whether there is change in voltage between terminals according to the temperature of the evaporator surface.

NOTE: This check should be carried out on the back probes of the thermostatic switch when it is in coupled state.

5. If above condition is not satisfied, remove the evaporator unit and replace the thermostatic switch when it is in coupled state.