Not sure about 05 fatboy, but on my bike 2011 Heritage Classic I had to remove the tank. My throttle and idle cables go through 3 wire looms along the backbone of the frame under the tank. No other way to get them out. Actually worked out great. Can see everything, don't have to worry about the tank im the way, plus I figured while it's off would be a good time to run the wires for my new l.e.d light kit! Why not? Anyway, if you do decide to go the other way .... sliding the tank... be careful you don't scratch up your rocker covers. Heard real nasty horror stories about that.