Hmmwv erratic oil pressure gauge troubleshootng

My 87 hmmwv 6.5 na oil pressure gauge is reading 90 to 120 lbs when engine is running. Reads 30 lbs before engine is running while waiting on wait light. It has a fresh oil change and all gauges are reading ok except oil pressure gauge. I changed gauge from my other hmmwv and it reads the same, gauge jumps around from 90 to 120 lbs. Any idea what the trouble is, thanks , Ralph

Sounds like either a grounding issue or maybe the sender wire is shorting out.

Take the panel that holds the gauges off. Look at the mounts that hold the oil gauge in place, there is a ground on there. Take it off and clean the surface contacts. Sometimes moisture gets to it and causes the jumping, high reading. I had an issue like that last week, and purchased a new gauge only to find it was the ground. Remember to use some sort of lubricant (silicone spray/ wd40) before pulling the connectors so you don't crack them if you end up having to replace the gauge.

I covered my escapades here:
http://www.steelsoldiers.com/showth...ure-gauge-wiring-sensor-sender-Lesson-learned

So I'm curious, what did the problem end up being?

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