What usually controls an oil pressure warning lamp?

Question

Quizplus · Accepted Answer

A ground switch is the most common method of controlling an oil pressure warning lamp. When the oil pressure in the engine falls below a certain level, the switch closes the ground circuit for the lamp, causing it to illuminate on the dashboard. This alerts the driver to the potentially serious problem of low oil pressure. While voltage drop and ground sensors can also be used to control warning lamps, they are less common in oil pressure systems.

What Usually Controls an Oil Pressure Warning Lamp