Low Oil Pressure Warning Indicator
WARNING: This page is about a different car, the 2004 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.
The oil pressure switch installed in the engine block is a resistive switch. A resistance of greater than 1000 ohms causes the low oil pressure warning indicator to indicate normal oil pressure. With no oil pressure, the resistance drops below 1000 ohms and the low oil pressure warning indicator indicates low oil pressure.