- Remove the coolant temperature sender from the engine.
Position the sender in a container of water on your stove, as shown in the accompanying illustration.
- Using an ohmmeter, measure and note the sender terminal-to-sender metal housing resistance.
- Slowly heat the water in the container and observe the sender resistance exhibited on the ohmmeter. The resistance of the sender should smoothly and steadily decrease as the water temperature increases.
- If the sender resistance does not react as noted, replace the sender with a new one.