Coolant Temperature Sensor/Switch (For Computer): Testing and Inspection

Fig. 12 Testing Water Temperature Switch:

1. Drain the coolant from the radiator. Unscrew and remove the temperature switch from the water outlet housing.
2. Place the switch in a pan of cool, (below 118°F), water and check continuity with an ohmmeter. There should be continuity between the terminal and switch housing. Fig. 12

Fig. 13 Testing Water Temperature Switch:

3. Heat the water to above 140°F and check that there is NO continuity. Fig. 13
4. If not as specified, replace the temperature switch.
5. Apply a suitable sealant to the switch threads and reinstall.
6. Refill the radiator with coolant.