I have an all-original 1953 3800. I have owned it for some time and am pretty familiar with the mechanicals. But... My fuel gage did not function and I found the float to be sunk. I installed a new float and all worked ok but soon it began to show "full" all the time. I have found that if I fiddle with the wire and terminal that goes into the sender then the gage registers properly. However no matter how I tighten or loosten or fiddle with this connection in a few miles the contact is lost again and tank reads full. Where is the problem?