ok so the gauge is not working and i am getting ready to take the tank down and try to replace sending unit. i am looking for any advice you can give before i start.
I am in the middle of the same dilemma. Mine wasn't working either, '81 CJ5 , so I dropped the tank and put in a new sending unit. Still doesn't work. The old sending unit still works. I hooked up a multimeter to it and the resistance varies as the float is raised and lowered. I'm down to tracking wires from the sending unit to the gauge and then I will test the gauge itself. Dropping the tank is not that hard but it's no picnic either. I would try testing the wires, ground and gauge first if I had to do it over.
83 CJ7 350 tbi, TH350, D300 twin sticked & clocked, narrowed Chief D44 Eaton Elocker & Moser shafts, Explorer 8.8 Detroit locker, 410's, RE 4.5" spring lift 1" body lift, 35" Claws, cage tied to frame, Corbeau baja seats, HD tie rod and draglink, u-bolts flipped, custom skid plate and sliders, Warn 9.5ti winch with Amsteel synthetic line
Does your voltage meter work? There is a wire between the voltage meter and the gas gage. The voltage meter actually provides about 5 volts of power to the gas gage. It is not uncommon for the grounding at these gages to be the problem.