i have a 93 chevy 3500 CC dually, 6.5 TD. The fuel gauge maxes out and while driving it comes down to where its supposed to be and jumps back and forth. Where can I start looking for the problem?? Any common places? Is it a bad ground or a grounding issue?

 

Sending unit in the tank probably GM gas gauges are never correct!

 

Yep, what he said. I had a 2000 GMC 3500 crewcab that did the same thing. It was indeed the sending unit in the tank.

 

alright! thanks guys!