Rick,
The sending unit doesn't usually require a ground as it 'can' get that ground through the screws attaching the sending unit to the tank, then through the tank to the body, then through the body hopefully back through the frame to battery. If any of these routes are insulated, its a No-Go deal.
The quick check is to run a wire from one of the screws holding the sending unit to the tank right back to battery NEG.
Looking at another truck site I see this problem being mentioned in the early part of '06.
Stuart
Last edited by atomarc; 02/04/2008 4:23 PM.
