Originally Posted by SHOtime2511
My best guess was something in the sending unit also.
Any advice for checking the sending unit,remove the bed or drop the tank?
Its easier to remove the bed IMO.
To check the sending unit, Grab a buddy and a test light. Pull the connecting wire off the top of the sending unit, have your buddy turn the truck on. start testing wires until the gauge goes up to full. If you can find the wire where it makes the gauge go to full, you need a sending unit, if not, it could be the gauge or the wires.