Oil Pressure Warning Indicator

The low oil pressure indicator light works in two ways: it flashes continuously following a momentary loss of oil pressure, or it goes on and stays on with a complete loss of oil pressure. When the ignition switch is in RUN or START, battery voltage is applied to the low oil pressure indicator light. If the engine is not started, the closed engine oil pressure switch provides a ground, turning on the light. When the engine is started, the alternator provides an "engine running" input to the integrated control unit. With normal oil pressure, the engine oil pressure switch is open and the low oil pressure indicator light does not go on. If the engine oil pressure switch closes momentarily (more than 0.5 seconds) but then opens again, the YEL/RED wire at the integrated control unit will sense ground through the switch.

The integrated control unit will then provide and remove ground for the low oil pressure indicator light through the YEL/RED wire. The light will flash on and off until the ignition switch is turned to OFF The flashing feature will not work until 30 seconds after the "engine running" input is supplied by the alternator. This delay avoids unnecessary indicator operation. If engine oil pressure falls below 4.3 psi and does not increase while the engine is running, the engine oil pressure switch will stay closed. The low oil pressure indicator light will then go on and stay on.