Someone should have the Fatbob wiring diagram for you. You might want to say what year and if its an import... Btw, my StreetBob (imported) had three wires in there - damn yanks have an extra one for blinker brakes or some such shit.  Caused me all kinds of hassles (stuck on blinker) until I just cut the third wire

 If its an import, just disconnect the running lights from the bulb holders. 

Strange how just one stays on! Un less ne still has the wrong globe!
Also check the wiring under the rear funder to make sure the tyre hasnt worn through the insulation on the rear indicator wires!