[chevy_mike]

If you take the wire off the sending unit and touch it to ground, with the key on, the gauge should move to empty. Remove the wire from ground and it should go up above full. If it does this, likely your gauge is working and the problem is the sender. Remove sender, hook tan wire to it and run a jumper from the sender body to ground. Move the sender by hand and see if the gauge moves with it. If not, then sender is likely bad. If it moves correctly, then your sender is not grounding correctly.

If neither of these things work, likely some bad wiring/contact in the gauge panel to fuse block.