Fuel Gauge stuck on Empty

Fuel gauge stuck on Empty
I have a 1992 Mercury Tracer stationwagon automatic with A/C, Red with Red interior, only 60,000 miles (because I live in Hawaii) and my problem is this ........ My Fuel Gauge is stuck on empty. First, when I would fill up with gas it wouldn't go completly to Full and over the course of a couple months would progressivley go less and less to the Full position (i.e. 3/4 then 1/2 then 1/4) until it wouldn't register anything except completly empty. I sourced a used fuel pump assembly from another 1992 stationwagon whos fuel gauge worked just fine and after putting that working fuel pump assembly into my car, the problem still persists. The fuel gauge is still on Empty. I use the odometer to let me know when to fill up, but I'd like to have the "LOW FUEL" light to be off. :banghead:

Is the sending unit for the fuel guage part of the fuel pump?
Are the electrical connections to the sending unit good and free from corrosion. Is the float good? If it leaks and is full of fuel, the float will sink. When installing a sending unit, care must be used so it doesn't get stuck or hung up.

I would check for a ground wire near the fuel tank as a coroded connection can cause this type of problem as you replaced the sending unit. Remove it clean with sandpaper reinstall and coat with greese. It could be close to the unit in the tank or on the unibody. If you ground the sending unit wire does it move your gage not a hot wire. It can be a bad gauge in the panel.

Sounds like a resister in the gauge itself, it cant be the ground cuz if the ground wire broke loose than the gauge should read full!!! It would be easiest to go to the junk yar and pull a gauge out of anoughter vehicle.....OR the float arm in the tank rusted and fell off finally, This would explane the less and less reading!!! "Sounds a though it bent as it rusted"