Operation CHARM: Car repair manuals for everyone.

Component Inspection


1. Place coolant thermosensor into a container with water.
2. Install suitable ohmmeter onto coolant thermosensor and measure the resistance.
3. With water temperature at 68 deg. F., resistance value obtained should be 2-3 kohms.
4. Heat water until temperature is 122 deg. F. Resistance value obtained should be 700-1000 ohms. If resistance values obtained are not within specification, replace coolant thermosensor.
5. If the test is to be conducted in the car, a cold (shop temperature) thermosensor will be 2-3 kohms and a fully warmed up thermosensor (approx. 180 deg.F) will be 250-400 ohms.