Oil pressure gauge pegs to max

[Bmarler]

Thank you all for the suggestions and help. After many tests and repeat test and even though I swapped senders to wire harnesses with presumably positive results, I swapped senders to motors and now the stb side works and the port side does not.
Original stb side sender is faulty.
Now to find one.

Tranny pressure as well?

 

[The Dread Pirate Robert]

Yes

 

[Dougcole]

I just went through something similar to this on my Faria gauges. It's very frustrating as gauges can be super sensitive and there are multiple opportunities for shorts, especially if the gauges are daisy chained. With me it turned out to be BOTH bad sender wires and bad grounds.

It seems most of your focus has been on the signal and positive sides of the circuit. I scanned through the thread quickly and may have missed it, but have you tried running a clean ground straight to the gauge that is not working? Is there a ground buss close by that you can tap into? It really sounds like a grounding issue to me.

 

[MichaelD]

If the gauges on the dash are pegging, as you described, that's an indication that they are seeing zero impedance in the circuit, i.e. a short to the DC V supply (12 or 24 ). So, look for that.

I had that symptom, but in my case it was due to a shorted sender that was a new replacement for a failed sender. Had to get another and then it worked fine.