I am having my gas tank cleaned of rust and coated, so it is at the radiator shop. The guy at the radiator shop said that he checked the sending unit and that it looked fine, and that he thought that the problem was electrical. Where else could the problem be? I don't know anything about how this stuff is hooked up.:confused:

Ground,gauge,sending unit,wire going to the gauge.Do a search on old post i was haveing a problem and these guys were a big help....:beers:

Very good info here:
http://www.chevelles.com/techref/ftecref18.html

Mine tested alright too,but when i took it apart the little copper windings on the sweep contact (where the float connects inside of the tank)were coroded and the strap was about to fall off.my screen was fallen apart inside,so i replaced it .i bought the cheap one from ground up works fine!