Rally dash oil pressure gauge issue.

You could have grounding issues. Keep in mind that an ohmmeter uses a very low current to measure the resistance. This can fool you on wiring harnesses.
Thats a good point do you knw where the instrument panel ground is? as for now I do know my temp and electical guage work, fuel I dont have an idea as I am running engine off a gas can. it did work when I had it on the road though,actaually all the guages worked LOL! I may have to pull the cluster again. I really dont want to but. If it is the guage I may do the modern conversion of all of them I had heard the voltage limiter can cause a fire.