Trip Computer, Oil Pressue Gauge, Volt Meter HELP!
 

Hello I own a 2003 Nissan 350Z Enthusiast model that I purchased used. There was no evident problem with the car other than a very annoying problem with the trip computer and the other two gauges. At first the above mentioned gauges would not even turn on. Finally I took the car in to get checked at a local shop and when the guy checked the wiring behind the double din steroe he said the reason they were not turning on was because they were not connected. Well now they do turn on and now the issue is as follows; the volt meter appears to be working like a champ no noticible problems there at least non that I can notice, the oil pressure gauge is acting all kinds of weird it does not have a constant read and most of the time is just stuck way beyond 120 psi never actually chaning in position regardless of the car's acceleration nor speed. Also, the trip computer does turn on and after initially turning the car on goes through the sequence of different setting that it has and finally stops back at the "mph" setting which never changes from the "---" reading. I have tried changing this with the trip computer button on the gauge cluster (right hand side) but does not change at all and also the illumination buttons for the gauge cluster (left hand side) do not work. I have pulled each fuse individually and they all seemed to be in perfect working order, at this point I do not know where else to turn. Please any advise would help.

Does the car have an aftermarket radio? Sounds like they messed the wiring up when they installed it to me. Get a manual and check the harnesses if I am right.

Yeah the stereo is after market Pioneer double din touch screen. Will that cause the brightness buttons and the trip computer to not work on the gauge cluster?

The radio is interconnected with many things. I can't say that is the reason 100% but it seems a fair place to start.

Ok I'll have to pop all that stuff out and see if there's anything sketchy on the connections.