I am not sure if Lincoln used an electrical fuel guage for that year or a float and feed wire in the tank, but if it is electrical, you will have to take it to an automotive electrical technician to have it fixed. If it is not electrical then the float in your gas tank may be stuck, or the cable may have become detached or rotted. In this case it could mean that your gas tank has to be dropped and have the float removed and serviced, the dash may also have to be removed.
I very much doubt it.
have you checked the fuel gauge itself to make sure it is working
Fan Relay
why doesn't my rpm gauge and temp gauge, fuel gauge not work
You might need a new thermostat or heater core.
CHECK WIRE
DO YOU HELP SETUP GRANTS OR MAKE SUGGESTIONS ON WHAT GRANTS WORK ?
No.
Your sensing unit may be broken inside of your gas tank. If it is, you would need to purchase another tank.
Happened to me once too. In my case it was simply a blown fuse. Check your owners manual for this fuse located under the rear seat.
An alternator does not need a gauge to work. It is used to monitor the output of the alternator.
If it gets to hot the thermostat wont work. you need to repace it and the gauge will work again.