Radiator Cooling Fan Temperature Sensor / Switch: Testing and Inspection

Radiator Fan Switch

Testing

WARNING: Removing the radiator fan switch while the engine is hot can cause the coolant to spray out, seriously scalding you. Always let the engine and radiator cool down before removing the radiator fan switch.

NOTE: Bleed air from the cooling system after installing the radiator fan switch.

1. Remove the radiator fan switch from the thermostat housing.




2. Suspend the radiator fan switch in a container of water as shown.
3. Heat the water, and check the temperature with a thermometer.

CAUTION: Do not let the thermometer touch the bottom of the hot container.




4. Measure the resistance between the A and B terminals according to the table.