FLACHUSNRET

I have a 1981 which I drove this morning for the first time in several weeks. The outside temp was in the 50s but this car is always garaged in a temperature controlled garage. I have owned this car for 10 years. The gas gage is not working. I have never experienced a problem with this gage before.The needle is maxed out way past the full mark. The gage needle is in an almost complete horizontal position. Not knowing how much gas I had in the tank, I headed straight to a gas station and got 10 gallons. That made no change. I also tried tapping gently on the gage and made some rapid stops and starts to no avail.
What should I do first to isolate the cause of this problem?
Is there a fuse that controls this gage? All other gages are working correctly.

StDomingos

You have a problem with the ohms signal from the sender or at the gauge.

Willcox provides an excellent diagnostic document here;

http://repairs.willcoxcorvette.com/w...it-testing.pdf

Lachymac1

I believe this should work for you in isolating the issue (I've done this on other old cars that I've worked on). Take off the spare wheel and carrier and you will see the brown wire I believe going to the sender unit at the bottom of the tank, (I believe it is still at the bottom for an 81). Have someone sit in the car with the ignition on and ground the brown wire, the fuel gauge should jump to full, if it does then you know the gauge should be fine and that the wiring to the sender should be serviceable and your sender unit may be the issue.

FLACHUSNRET

Thanks, that link is very comprehensive and should help me pinpoint my problem.