Oil problem 2000 ford ranger

If you mean you're seeing LOW OIL PRESSURE on the meter, its likely the sender wire or connector is loose/bad or the sender is bad. A second possibility (if you're LESS lucky) is that the oil pump or its pickup arm is JUST LOOSE ENOUGH that once the oil heats up and thins out a bit,enough is leaking out of one of those 2 places that the pressure drops. The worst case possibility is that the crank and/or cam and or wrist pin bearings are so worn that the pressure drop is coming from there once the oil warms up. I'd check the connection first, then if that not OBVIOUSKLY bad, replace the inexpensive sender, and hope for the best-you may get lucky.