GMC 10045847 Coolant Sensor

The coolant temperature indicator system includes an instrument panel lamp and a coolant temperature sensor or sender, situated at the left rear of the cylinder head on L4 engines, and at the rear of the right head on V6 engines. In place of a temperature sensor, the transducer replaces it if a temperature gauge is used on the instrument cluster. Where there is unusual indication or fault development, check first the coolant level in the system and then ensure that connecting wiring between gauge and sender unit is secure. When turning the ignition switch to the ON position with the starter motor turning, the indicator lamp should be illuminated (Overheated engine indication). The lamp may not be lit if; the bulb is burned out, the ignition switch is faulty or the circuit is open. Once the engine starts, the lamp should go out and remain so unless it overheats. The lamp may fail to go out because of a defective temperature sender unit or a faulty ignition switch or grounded wiring between the lamp and the sender unit. If you were going to change this Sensor unit, it would simply be unscrewed from the cylinder head after which another one could be installed in its place. There will be some loss of coolant so check levels after replacement has been installed.