Oil Pressure Gauge: Testing and Inspection

Disconnect oil pressure gauge electrical connector from the sending unit, then connect a 12 volt test lamp between the gauge connector and ground, then turn ignition to the On position. If test lamp flashes, the instrument voltage regulator is functioning properly and the gauge circuit is not broken. If the test lamp remains lit, the instrument voltage regulator is defective and must be replaced. If the test lamp does not light, check the instrument voltage regulator for proper ground or an open circuit. Also, check for an open in the instrument voltage regulator to oil pressure gauge wire or in the gauge. If test lamp flashes and gauge is not accurate, gauge may be out of calibration. Replace gauge.