used to hook gps up to cigarette lighter but now will direct wire. Ive pulled off the front fairing cover and looking for a power source to hook up the gps positive and neg wires. I thought there would be and extra plug or something but don't see anything.
Right up near the headlight is a power wire with a plug already on it and there is a ground right beside it. I hard wired my cigarette lighter with these leads because I blew fuses when using the lighter socket for a power pick up. Both wires slide right onto the prongs that power the lighter socket.
I wish I had a picture but these two wires are right in the headlight loom.
I had a 2005 Road King had the same problem. I was using a Garmin. Before I cut the end off the plug I called Garmin and they said if I would have cut the plug off. And wired direct that it would have blown the GPS so I used a female plug with the end cut off then plugged the GPS into that. And then wired the female pug direct. I know that this doesn't help with the problem you have but thought I would just pass it on.
Good luck
Most add on accessories have a built in voltage regulator( usually 3.5 to 5 volts) in the lighter plug. Feeding them with 12 volts is a sure way to test time to destruction.