Gas gauge pegs to full

[Guest]

Hey guys,

I just finished pulling the dash from the bird and after reinstallation of all the gauges the has gauge pegs to full after key is turned to the on position. Right now I have the constant voltage regulator for the temp and gas gauge hanging under the dash because I want to relocate it to a better accessible area. Could it be a grounding issue with the constant voltage regulator causing the issue.


I also finished rewiring the rear tail lights and found some loose grounds in the rear. Could one of the grounds be for the rear sending unit for the gas gauge?

Gas gauge was working prior to pulling the dash.

[Tbird1044]

If my memory is correct, if you ground the wire at the gas tank sending unit, the gauge will read FULL. This is exactly opposite of GM.
I'll attach a pretty good pic of the instrument gauge wiring. Copy it to your computer, so you can enlarge it for a better view. Make sure all the wiring is correct. Also, an easy check to see if the CVR needs to be grounded, is to run a ground jumper to the hanging CVR. See if things change. If things don't change, start checking the wire going back to the gas tank sending unit. It sounds like it is grounded.
Nyles

[simplyconnected]

Yes, the CVR must be grounded. You can burn out your gauges if you don't ground the CVR because the gauges are designed to be run on pulsating 12 volts. The CVR works like a flasher unit; an internal heating element causes 12 volt current to pass half the time and turn off half the time, giving a 50% duty cycle.

If you have no ground on the CVR, you are putting constant 12 volts on your gauges. They won't last long that way.

The sending unit in your gas tank depends on solid ground passing through the body, to the battery. I always run a separate copper stranded wire for my grounds, like modern cars have. - Dave

[Tbird1044]

Dan:
You never mentioned if you are using the original CVR or have upgraded to the solid state model. Most of the guys here recommend using the solid state CVR's to add additional protection for your gauges.
Nyles

[simplyconnected]

I believe Dan is using the original mechanical CVR.

Dan, I offer a good price on solid state CVRs to paid members of Squarebirds.org. I convert them myself. - Dave

[Guest]

I am currently running the original CVR. I will ground it out tonight and make sure everything is working. Hopefully my gauge is not burnt out. I need to replace it either way in the near future since the Temp gauge needle is broken.

[simplyconnected]

... the Temp gauge needle is broken.

Huh? How on earth did it break? The only needle on a pivot shaft is the speedometer. The others are simple sheet metal.

Wait a minute... How is the needle broken? Can you take a picture? Send it to:
simplyconnected@aol.com

[simplyconnected]

What ever happened with this, Dan?

[Guest]

CVR was not grounded causing it to PEG to full. I went ahead and mounted the CVR where the car amplifier for the radio was installed under the driver side dash. Much easier to access now and the gauge works perfectly.