Could be the fuel sender, bad earth, short on the wiring, fuse or at worst the gauge :?
Does it read constantly full or empty?
I drove my for 4 years without a working fuel gauge...even 5 weeks through Iceland...just fill it up every 300 miles
If you have a friendly parts supplier ask them if you can have a gauge on sale or return & elimate that, it's the most expensive part :roll:
Welcome to life with the Green Oval :D