Radiator Cooling Fan Temperature Sensor / Switch: Testing and Inspection

Fig. 34 Thermo Sensor Inspection:

1. Immerse sensing end of sensor in hot water with a suitable circuit tester connected to sensor terminals, Fig. 34.
2. Moderate water temperature while monitoring continuity.
3. If condenser fan sensor is being tested, results should be as follows:
a. Continuity should exist when temperature is 196-210°F but should not exist at or below 189°F.

4. If radiator fan sensor is being tested, results should be as follows:
a. Continuity should exist when temperature is 178-192°F but should not exist at or below 171°F.

5. If results are as indicated, sensor operation is satisfactory; if not, a new sensor should be installed.