Temperature Sensor (Gauge): Testing and Inspection

Coolant Temperature Gauge Sender:

1. Disconnect the YEL/GRN wire from the sender.
2. With the engine cold, use an ohmmeter to measure resistance between the positive terminal and the engine (ground).
3. Check the temperature of the coolant.
4. Run the engine and measure the change in resistance with the engine at operating temperature (cooling fan comes on).

Temperature: 56°C (133°F) 85°C (185°F)-
["C" mark] 100°C (212°F)

Resistance: 142 Ohms 49-32 Ohms

5. If obtained readings are substantially different from specifications above, replace the gauge sender.