Oil pressure light not turning on when starting the car

Welcome back to 2CarPros. It could be as simple as the lamp for the oil light has blown. Or the light sender switch could have failed. The easiest way to determine which is to simply unplug the switch connector. It is located on the oil filter adapter. Inside it there is a single gray wire. If you connect a jumper wire from the contact in the connector to a good ground and turn on the key the light should come on. If it does the switch is bad. It is easy to replace, it unscrews and a new one screws in and the connector goes back on. If the light doesn't come on then it is likely the LED in the panel is bad or there is an issue with the board inside it. Those are not user replaceable items though. I would test the switch first. They do fail a lot.