i have an issue with my gauges on a 78 elkie. to best explain it, the oil pressure gauge works when it wants to, usually it's maxed out in the reading.
the water temp gauge is the one that worries me, at startup, it reads right, but after 15-25 minutes, the hits 260 and keeps going. tonight it did it again, but this time full peg, like another full section of the short sweep. (about an extra 80 degrees in angle past hot)
the gas gauge reads about 3/4's when i fill up the tank. the voltmeter almost always reads 8volts, not matter if i'm cruisin or on the highway.
by the way, is there an adjustment for the bouncing speedo? on the highway, at 65 (i hope that's the right!) it sways from 55-75, i usually take the average to guess my speed.

thanks,
andy

Not real specific, but the first thing I would do is to check the grounds throughout the vehicle. Start at the battery and go through frame to body connections. Make sure the gauge panel connectors are clean and secure. I might also unplug the harness at the firewall and clean the contacts with a small wire brush and contact cleaner. Also clean the connectors at the alternator, temp & pressure senders.
The speedo might be a bad cable.
Good luck.

i

I had somewhat the same problems right after a new crate engine install. My worst one was the oil pressure gauge. It would work, then not at all, etc.

I was all ready to purchase a new gauge, take it to the dealer to have installed, etc., when Ernie (87 El Camino) suggested I try just changing the sending unit. That was the problem! Changed the sending unit, and it has worked like a charm ever since. . . :P

I did go back after Ernie's advice, and unplug and clean everything I could get my hands on, and all seem to be working great now. They are all (except for the sending unit) the original gauges and wiring (it's an 84) and nothing (knock on wood 8O ) so far. . .

I think Bob is on the right track. Clean - Clean - Clean, and then clean some more. . . :cool: One thing I have learned on here - these guys all have forgotten more knowledge about El Camino's than I will ever know. When they suggest something - it has been my experience, to give it a try. . .jmo 8)

Don

In my car, multi gages acting up was due to a little crud corrosion in the connector to the instrument cluster, nothing unusual for a 20 year old car. That connectoion, plug contacts resting on bare tabs of the printed circuit, is not a great idea for durability. I cleaned the connections with contact cleaner from Radio Shack and a little scotchbrite pad and the gages have worked fine since.