Fuel gauge

More than likely the sending unit in the gas tank may need replacing. It has a float than moves with the gas level.

Might as-well replace the whole sending unit verse just the float or repairing just the float as it will more than likely fail again and since pulling the tank out you also have to pull the sending unit out anyway and its the same cost at a repair shop minus parts or the same work at your own shop or home to do the repair. I would stay away from the cheap fix parts kits that sell just the pump and/or floats & strainer that you have to install yourself to the main sending unit body and buy & install the entire sending unit, its worth it in the end.