Fuel gauge problem

[wydomkr]

The 80 Scottsdale that I picked up a few weeks back, I have been going thru and fixing some of the little problems and I have one I need some input on.

It was on fumes when I picked it up, needle was below E. First stop was to the gas station. Put 10 gallons of gas in it and the needle just jumps all over the place. My first thought was the sending unit in the tank, but it does it when the truck is moving or just sitting. The truck doesn't even have to be running, you can just turn the key to the on position and it starts to move around.

Could it still be a sending unit issue? Possibly the gauge in the dash or a ground issue?

Will hopefully have pics up by this weekend, had to buy a new camera.