Coolant Temperature Indicator Diagnosis - Gauges and Warning Indicators

If the Coolant Temperature Indicator comes "ON" with the engine running, but not overheated:
^ Remove the connector to the Coolant Temperature Switch/Sender. If the indicator goes "OFF", install a new Coolant Temperature Switch/Sender.
^ If the indicator remains "ON", check CKT 35 from the Coolant Temperature Switch/Sender and the Ignition Switch for a short to ground (also from Multi-Function Chime Module if equipped). Also check that the Instrument Cluster printed circuit has no cracks or flaws and is mating properly with its connector.

If the Coolant Temperature Indicator does not come "ON" while starting the engine, and the bulb is good:
^ If equipped with the Multi-Function Chime Module, disconnect Module.
^ Ground CKT 35 at connector C1 terminal "C" of the Ignition Switch. If the indicator comes "ON", the circuit is good. Replace the Ignition Switch.
^ If the indicator does not come "ON", check CKT 35 and the Instrument Cluster printed circuit for an open.