Coolant Temperature Sensor/Switch (For Computer): Description and Operation

This sensor incorporates a thermistor in a brass housing with an integral wiring connector extending from the body. This sensor is installed in the heater outlet fitting of the intake manifold. The thermistor is a resistor whose resistance value is high at low temperatures and decreases as the temperature rises. The computer applies a voltage to the sensor and monitors the resultant voltage drop across the thermistor.