Check Engine Oil Pressure

The low oil pressure lamp comes on to warn the driver when the engine oil pressure is low. Battery voltage is applied to one side of the bulb. A ground path is provided by the engine oil pressure switch. The engine oil pressure switch contacts are closed when the engine is OFF or the oil pressure is below 28 kPa (4 psi). After the engine starts and normal oil pressure builds up the engine oil pressure switch opens and the lamp goes out.