Oil Pressure Indicator Lamp

To test the indicator lamp, turn the ignition switch to RUN. DO NOT  start the engine. The lamp should come on. Start the engine. The lamp should go out, indicating that the oil pressure is OK.

To test the oil pressure switch on the engine, turn the ignition switch to RUN but do not start the engine. The indicator lamp should come on. If the indicator lamp does not come on, remove the wire from the switch terminal and connect the wire to ground. If the lamp now comes on, the oil pressure switch is inoperative, or not properly grounded to the engine. If the lamp does not come, the warning lamp is burned out or the system wiring is open circuited.

If the lamp stays on with the engine running and good oil pressure, disconnect the oil pressure switch lead wire. If the lamp goes out, replace the oil pressure switch. If the lamp does not go out, check for a short circuit in the wiring from the oil pressure switch to the bulb.