couple guage electrical questions

try grounding the wire that hooks to gas float. the gauge should quickly rise to full. if not then unhook that same wire at the gauge, hook a jumper to the teminal and ground that. if the gauge rises to full then the wire between the gauge and tank is bad. if the needle doesnt rise then the gauge is bad or no power is gettin to the gage.
if the gage rises when grounding the wire at the tank then the ground strap between the tank and frame is bad