Oil Pressure Warning Lamp/Indicator: Description and Operation

Circuit Description
When the ignition switch is in the ON or START position, battery voltage is applied to the indicator bulb from fuse 28.

Oil Pressure Indicator
When the oil pressure is low (oil pressure switch is closed), ground is provided to the oil pressure indicator bulb. The oil pressure light comes on when the engine is not running and the ignition is ON. In that case, the pressure switch remains closed and the indicator light stays on.