1976 Scamp fuel gauge problems

Well, I got to poke around in it some more today. I get full battery voltage at the wire at the tank and the gauge does not move when I short that wire to ground. I will say that when I have my meter connected to the tank and bounce the back of the car, the reading does move, but it still shows close to empty with a full tank; sunken float. But now, if the fuel gauge is burned up as it seems with full battery back to the tank, wouldn't the temp gauge be the same way? The temp gauge works just fine even though I thought it runs off of the regulator. Either way, I'm gonna pull the cluster when I can and see what's happening. Right now I'm making payments and I won't official own the car for another couple of months, so I can't do anything too big to it just yet.