So my fuel gauge will sometimes bounce between full and empty...I will go back to where the wire runs from the top of the tank to the back of the boat..and move it and it goes back to where its suppose
to be..does this usually mean its a bad ground or a bad sender???

Bad/loose ground. Could be on the stud or could be where it grounds to the block or wherever your ground is. The Baja sender is a pretty simple sender and don't think I've ever heard of one going bad. I'd make sure the connections are good and tight. Good luck.