The coolant temperature indicator system is composed of a light or temperature gauge mounted in the dash and a coolant temperature sending unit mounted on the engine. The coolant temperature sensor is located at the front of the engine, next to the
Thermostat. On the models covered, there is only one coolant temperature sensor, which functions as an indicator for both the PCM and the instrument panel. If an overheating indication occurs, check the coolant level in the system and then make sure the wiring between the light or gauge and the sending unit is secure, and all fuses are intact. When the ignition switch is turned on and the starter motor is turning, the indicator light (if equipped) should be on (overheated engine indication). If the light is not on, the bulb may be burned out, the ignition switch may be faulty, or the circuit may be open. As soon as the engine starts, the light should go out and remain out unless the engine overheats. Failure of the light to go out may be due to a grounded wire between the light and the sending unit, a defective sending unit, or a faulty ignition switch. Check the coolant to make sure it is the proper type. Note: Plain water may have too low a boiling point to activate the sending unit. Disconnect the electrical connector from the sensor. Wrap the threads of the new sensor with Teflon tape to prevent leaks. Unscrew the sensor. Be prepared for some coolant spillage. Install the sensor and tighten it securely. Connect the electrical connector. Check the coolant level after the replacement unit has been installed and top up the system, if necessary. Check now for proper operation of the gauge and sending unit. Observe the system for leaks after operation.