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

The coolant sensor, located on the thermostat housing, gives the computer information on engine temperature. A signal is supplied to the computer which will cause the spark plugs to fire at a fixed amount of advance during cranking only. Amount of advance is determined by the position of the start pick-up coil. The run pick-up coil functions the same except that its signal is not recognized during engine cranking.