im not sure if my fuel gauge it bad or my sending unit is bad in my 150. i was wondering if it would be easier to rig up a new fuel gage and sending unit sens i cant find a sending unit any where

 

Perhaps this sending unit is the one you need.

I entered: 1985 Ford fuel gauge sending unit, 4.9 liter engine.

Buy Dorman - Champ Electronic Fuel Gauge Sending Unit 7-199 at Advance Auto Parts

To check gauge operation remove wire to sending unit at the gas tank, and ground. Turn the ignition key to the On postition. You should see the needle move to Full.

 

9 times out of 10 if the gas gauge is not moving then it,s the sending unit is either stuck or the float has a hole in it and filling up with gas, causing the float to drop to the bottom ! did you try shaking the truck to see if the gauge moves ? the float might be stuck !