I'll agree you may have 2 or 3 issues but if I understand correctly you started with 1 being the fuel gauge. So I would back track and try to figure out what is causing the other two issues which sound A LOT like a ground problem. Once that is resolved I would go back to the fuel gauge which again, I'll agree sounds like a grounded sending connection or wire. One can disconnect the wire at the sending unit or preferably at either the rear harness connector or instrument panel connector until the other two issues are resolved. Doing so will also allow you to ohm out each section of the harness.
Might also wat to look at this post
https://board.moparts.org/ubbthread...temperature-gauge-issue.html#Post3086628keep us posted
