I'm hoping someone can help me with a very frustrating non-working fuel gauge in my 52 Chevy Styleline. Here is the background... I updated the vehicle to 12 volts, installed a 12 volt replacement fuel gauge in the factory dash, new sender in the new poly gas tank, and ran a new wire from the sender to the gauge for good measure. I also ran a ground wire from the tank sender in the poly tank to a the underside floor of the trunk. The replacement gauge is for a 12 volt system so no in-line voltage reducer is needed to reduce it to 6 volts. Lastly, i added about 8 gallons of fuel to the new tank. Here's where i am now... 1) When i turn the key to the one position the fuel needle dropped to empty and stayed there, even when the key was turned off. 2) If i turn the key to the on position and remove the ground wire that goes from the tank sender to the trunk floor, the needle jumps to to full. If i leave the ground wire off and turn the key off, the needle drops to half full. Turn the key back on, it jumps to full. Reattach the ground wire at the sender and it goes back to empty. I trying to figure out where the problem lies... the sender or the gauge? Any other tests i can do to single out the issue?