I have a 2005 fatboy, the fuel gauge light works and the needle goes up and down when you turn on the ignition. But it always reads full when the bike is turned on. (Even if the tank is empty) Brought it to harley and they charged me 75$ and said they cleaned out a connector and now it was working. The gauge appeared to be working, the tank was full from harley and read full.
After riding quite a bit the needle never went down.
I took off the center console and loosened the access plate to the tank. i disconnected the harness that goes down in the tank and moved around the access plate with all the components connected. Put it all back together and turned it on and it worked. The level indicator float was stuck and that was the problem.

 

This is a fairly common issue. The float sticks causing the gauge to not read correctly.

 

From what I'm reading, it sounds like they owe you some money. But you'll never get it.