[tubman]

Same old problem. Ford gauges use the "King-Seeley" system which works differently from most other systems. Most (probably all) replacement sending units are the resistance type and won't work well in Ford systems. Touching the wire to ground should make the gauge move. If it doesn't, either the gauge or the wire to it is bad. Try a jumper from the terminal on the gauge to ground. No action, the gauge is bad; if the gauge moves, the wire to the gauge is bad. Only touch the wire to ground for a short time or you will have other problems.