A wise man once said the only dumb question is one not asked so, here I go with a question that some of you might consider dumb. Lol. Is there some sort of fuel level sensor on the 1970 Cutlass Supreme? My cars gauge will say it has a half tank and then it runs out of gas and it is way over the full mark when filled up. The gauge itself doesn't seem out of place so I don't think that is the problem. A sticky float in the tank wouldnt make the dash dial overshoot the "full" mark so I'm lost from there. I'm looking for some pointers on how to fix this. Thanks!

 

Your sender (or sender wire) has too much resistance - it may need to be replaced, but you may get away with just cleaning up the rheostat windings and wiper.

See posts here and here for a little bit more information.

- Eric

 

Awesome! I will be definitely be fixing the problem. I'll be sure to update you on the fix. Thanks a bunch!