Also, if you're not popping fuses or catching on fire, you probably don't have a short. It's probably one or more bad connections or broken wires.
Agree, a short will usually blow the fuse to protect the wire or component. You probably have 2 separate problems. The fuel sender in the tank for the gauge would be suspect. And as for the dash lights, I would take a look at the switch first. Does moving the dimmer from dim to bright have any effect on the lights?