Simple Test

Disconnect harness connector from water temperature sending unit located in engine compartment. Connect a 12-volt, 3.4-watt test light between harness connector and ground. Turn ignition on. Ensure test light flashes and temperature gauge indicator moves toward "H" position. If test light does not flash and gauge indicator does not move, check wiring harness, and repair as necessary. If test light flashes but gauge indicator does not move, replace gauge.