I have a 1999 ram van, 1500 3.9 at 150k miles.
The check gauges light will flick on at least once during my 20 mile commute and usually goes back off in a couple of seconds.
Each time this happens the alternator voltage goes out and thought i saw the oil pressure gauge pinned on high once. The fuel gauge has also been stuck on full since just before the check gauge proublem started.

I checked the connections to the battery, alternator and any grounds i could find, also pulled the instrument panel, checked fuses inside the cab,cleaned the three wire clusters to the pcm under the hood and checked fuses in the relay box.
Five of the six relays were the same so i rotated them to a different location to see if i can spot a bad one. The only one left is the (Hvac Ignition Run only relay).

My best guess is the alternator is on the way out but I could be way off.
Does any one have sugestions on the most likley causes?
Thank you for your time!!!

 

Welcome to the website, I'm sure you will get your problem resolved here. I have got excellent advice here and saved alot of $$$$$$$$$. Good luck.

 

It sounds like you're missing the engine to body ground strap. You can make one and see if it solves the problem. Otherwise I would suspect the PCM is on it's way out.

 

Thanks for the replies... The engine to ground strap was there and gave it a good tug at each end. Its around 150 deg in Phoenix now so i did not spend much time cleaning ground ends if they looked good.