Faulty oil pressure gauge- replace gauge cluster?

[TROGDOR!]

So I'm finally getting around to posting this- my RX has a bad oil pressure gauge. It peaks just over 45psi and falls to zero at idle. I thought it was an engine issue, but it read exactly the same with the original EA82T, the CCR EA82T, and the N/A engine I installed. Every engine has had a different sending unit on it, so I know it's not the problem.

 

Installed the CCR engine in my other RX, and as soon as I fired it up the gauge shot almost to the top and maintained wonderful oil pressure. So now I KNOW the problem lies somewhere in my gauge.

 

Do I need to replace the entire gauge cluster to take care of it, or is there some kind of wiring issue that needs taken care of?

[DrKrazy]

I accidently shorted the sending unit to ground while the car was running on Project Cheap (stupid skid plate)..did that same exact thing to the gauge except it actually read negative at idle. Swapped sending units, wiring etc...nothing changed. So guessing you would need to replace the whole cluster, at least that's what I was thinking on PC. Said forget it and installed an aftermarket one which I trust more than any Subaru gauge anyways. But if it was in my RX, I would get another cluster for it since I love the car alot more.

[Snowman]

Yeah, you have to do the whole cluster. The gauge in my mom's old wagon died, and rather than get another cluster, we just put on an aftermarket gauge.