Coolant Temperature Switch

1. Turn ignition Off and disconnect wire from temperature switch.
2. Using an ohmmeter, connect one probe to a ground or to temperature switch ground terminal. Connect other probe to center terminal of switch.
3. On a cold engine, there should be continuity with a resistance reading less than 100 ohms. If not, replace switch. The charge temperature switch must be cooler than 60°F for this reading to be obtained.
4. On a hot engine (at normal operating temperature), there should be no continuity. If there is continuity, replace temperature switch or charge temperature switch.