Coolant Temperature Gauge

The coolant temperature gauge measures the current from a variable resistance sensor in the engine coolant jacket when the ignition switch is in the RUN position.

The sensor changes resistance with the coolant temperature. As the coolant temperature increases, the resistance of the sensor decreases.

For gasoline engines, the coolant temperature sensor is near the middle of the cylinder head, on the driver's side of the vehicle. For diesel engines, the coolant temperature sender is at the front of the cylinder head, on the driver's side of the vehicle.