My fuel gauge is not working correctly, and I am having a little trouble hunting down the problem. While driving down the road, it fluctuates between 3/4 and full all the time, no matter what the fuel level is in the tank. The previous owner had a new fuel sender put in, but that did not fix the problem. I have pulled the plug off the sender, and the gauge goes to empty. When I jumpered the wires on the gauge plug, the gauge goes clear to the full peg. It would seem like the gauge is doing what it should, so I am thinking maybe the new fuel sender is bad. Anybody have any other ideas before I go spend $100 on a new sender? By the way it is an 87 SDL.

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