I recently have been trying to troubleshoot my fuel gauge not working in my 68 chrysler newport. Everything is new as far as the tank and fuel sending unit. I figured it is the ground wire but when I took the old tank out there was only the one wire which was the hot wire. No ground wire or anything not even a piece of a torn wire could anyone help me out with this.

 

Usually it is a metal strap about 12" long that clips on the metal tube on the sending unit and the other end clips to the metal fuel line that runs along the frame You can use a length of wire and a pair of hose clamps

 

Does it go on the same tube the hot wire connects too I mean the blue wire that plugs into the sending unit.

 

have you checked the 5 volt regulator for the instruments? check this out
http://www.allpar.com/history/mopar/electrical2.html
OR
http://www.chargersourceguide.com/voltagelimiter.html