Try this for guage:
1--unplug this wire (Tan) for fuse panel.
2--take a jumper and hook to where it plugged in.
3--turn on switch
4--ground the other end of jumper and watch guage --if it moves guage ok
5--trace wire you unplugged back to tank and see if it is hooked to tank.
6--if ok plug the wire back into fuse panel.
7--disconnect the tan wire from tank (switch still on) and touch to ground-if gauge moves gauge ok--sending unit bad.
8--if in #4 gauge does not move check to see if you have gauge wire plugged into right slot. If ok check out printed circuit. If ok change resistor on back of guage--get buy it here-cheaper then a whole guage.
www.fix-a-gauge.com