Recently got my s5 turbo swapped GTUs running. Everything works well except the oil pressure gauge. When the yellow and red slotted connector wire is connected to the pressure sender, the gauge reads 50 psi, with the engine off and key on. When the car starts, the gauge reads 110 psi. I do have a high pressure regulator installed, but this does not explain the gauge reading at engine off.

Any ideas?
I have another sender I could try. Also considering an aftermarket gauge.

 

I will also note that the engine harness is a turbo harness and the driver's side harness is the original NA harness that came in the GTUs. The oil pressure sender itself is from the 13b turbo.

 

i would have a close look at the wire, usually its grounded on something. ground = high oil pressure.