1971 Road Runner Gauge Questions???

I have a 1971 Hemi Road Runner and the gauges went goofy a couple of weeks ago--I'm hoping someone in Moparts Land can give me some good advice.

My Oil pressure gauge is "pegged" all the way to the high side, my temperature gauge is pegged all the was to the low side, the fuel gauge is pegged all the way past full. However, the alternator gauge is working just fine.

I figured before I started tearing the dash apart, I'd ask around to see if there were any known fixes. I did replace the limiter but that didn't make any change.

Thanks a lot!

Call this guy-
John Manush
319-758-0100/ cell 319-601-9135
He tests and rebuilds clusters, met him at the Nats and he knows everything.
Good Luck, bob

Great advice, thanks!

Bad instrument voltage regulator. All three of those malfunctioning gauges are powered from that regulator. It's on the back of the cluster. Hard to get to when the cluster is still in the car.
Real Time makes an electronic version of the regulator.

http://rt-eng.com/rte/index.php/Main_Page

In the meantime, might consider disconnecting sender leads from gas sender, oil pressure sender, and coolant temp sender so as not to fry your gauges - especially fuel and oil pressure, since they're pegged.

Sorry, reread your post. Perhaps you pinched a wire on the VR limiter reinstall, or inadvertently grounded the posts on the fuel and oil pressure gauge sending unit side?

Agree with the post above...

Thanks Guys. Going to RTE for help!

I agree with the Voltage Regulator.

Check for + voltage on the back side of the guage. It should be around 5V.

Another problem is often wiring. Check for burned or crispy wiring.