1998 bonneville. the oil pressure gauge n lights came on so we changed the unit. the gauges/ lights have gone off but the gauges reads LOW PRESSURE/IN THE RED at idle. i took the unit out and checked the pressure with a gauge n it read at 60psi. so we put the sender back in and still the gauge reads in the red at idle but no lights are on. so i bought a wiring connector to maybe change the connection out but i wanna recheck the sending unit. HOW DO I CHECK THE UNIT? Im an automotive STUDENT so this is new to me.

I'd try a new sender. Your school don't have an SI system? I can get you the info if the new sender doesn't fix it. I think it will.

it already is a new sending unit. n im sure the school does hv whatever equipment is needed. i was just wondering if it could be that i bought a faulty unit or if its actually the wiring. i bought the wiring pigtail too.

Oil level switch and the oil sender both can turn on the light.
Here'* the flow chart for them and the wiring diagrams.

60PSI at idle seems high for a 1998 unless the engine is fairly new.

Does the in-dash gauge go higher when you rev the engine to about 2,000RPM?