67-72 Chevy Truck fuel gauge diagnostics 101

[Hoodogie]

I know this is an old post but I hope someone will direct me a little bit. Not being great at electrical work I have read the previous threads and checked some things out with my gas gauge. Let me start and say that the gauged worked fine before I removed the cluster to change the printed circuit on the back in order to get my dash lights working. When I reinstalled it the gauge was reading at three o'clock. I then reached up behind the dash and found out that I haven't tighten the nuts down on the gauge terminals. I don't know if I had the key on or not but as I was tightening the nuts the gauge went from 3 o'clock to 3/4 full and hasn't moved since. I checked the resistance at the tank and got 68 which is what I think is correct for the gas I think is in the tank. When I remove the tan wire from the fuse box nothing happens to the gauge. When I grounded the terminal nothing happens with the gauge. Did I blow the resistor when I was tightening the nuts up I'm stumped