1987 740 Turbo Oil Pressure Light on with good oil pressure

[Salomons Driveway]

After rebuilding the engine in this 1987 740, I was able to drive it for several weeks, but now the oil pressure light is constantly on. I checked the oil pressure with a mechanical gauge and it is fine: 80 psi at 2000 rpm. I then changed the oil pressure switch without any results.
If I disconnect the oil pressure switch wire, the light stays on instead of turning off like it would in my other car.
Is there a way to test the oil light circuit in the dashboard with a volt meter?
Does the oil pressure switch simply break the circuit for the light , or is it more complex than that?
Timothy Salomon

[lummert]

Maybe the wire to the oil light sender is shorted to ground.

[Salomons Driveway]

You are right. I finally took the car to a mechanic and he found the wires for the Air conditioner and Oil Pressure switch had been reversed- by me!
Someday I might be able to fix electrical problems.....
Timothy