Radiator Cooling Fan Temperature Sensor / Switch: Testing and Inspection

INSPECTION
1. DRAIN ENGINE COOLANT
2. INSPECT NO. 1 ECT SWITCH





a. Remove the NO. 1 ECT switch.





b. Inspect the NO. 1 ECT switch.
1. Using an ohmmeter, check that there is continuity between the terminals when the coolant temperature is above 98°C (208°F). If there is no continuity, replace the switch.
2. Check that there is no continuity, between the terminals when the coolant temperature is below 88°C (190°F). If there is continuity, replace the switch.
c. Reinstall the NO. 1 ECT switch.
3. INSPECT NO. 2 ECT SWITCH





a. Remove the NO. 2 ECT switch.





b. Inspect the NO. 2 ECT switch.
1. Using an ohmmeter, check that there is continuity between terminals when the coolant temperature is above 93°C (199°F). If there is no continuity, replace the switch.
2. Check that there is no continuity between the terminals when the coolant temperature is below 83°C (181°F). If there is continuity, replace the switch.
c. Reinstall the NO. 2 ECT switch.
4. REFILL ENGINE COOLANT
5. START ENGINE AND CHECK FOR COOLANT LEAKS