The Stovebolt Site Forums The Shop Area The Electrical Bay Bad Sending Unit?

Fellow Stovebolt members, maybe you can help and maybe you've heard this problem a dozen times. Anyway, here goes. I have a 49 Chevy truck that was converted to 12v. I replaced my old fuel gauge with a new 12v one, and I have wired it correctly from the gauge to the sending unit and the other wire to the ignition. I also have the sending unit grounded to the frame. Also all new wiring. I start up the truck and the gauge doesn't move (stays on empty). When I Disconnect the sending unit wire at the sending unit the needle on the gauge jumps above full. What am I doing wrong or could I need a new sending unit. I checked and it is a 30ohm sending unit. I'd appreciate your advice.