Well...Here goes! My analog fuel gauge stopped working recently on my 2009 Fatboy..the light for the gauge does work however. I searched the shop manual for any test I could do on the unit to figure out the problem, but not much there! Doesn't seem to be much info on testing the gauge here either.
Lot's of info on replacing both the gauge and the sending unit (If necessary) but not much info on testing. I read somewhere that the gauge itself works by reading the amount of resistance on the circuit sent from the sending unit. It would help if someone (in the know) could elaborate a bit on what the gauge should be reading if I throw an Ohmmeter on it. Like I said...not much info in the shop manual sadly!

 

put ohmmeter on the sender wire and ground .move the float up and down should see a ohm change . no change , sender is bad

OR ground the sender wire , gauge should go full empty or full/full ..
if the gauge moves the sender is bad , if not , then the gauge is bad , or lost power.