I did the same thing a few years ago but used a cigarette lighter outlet style connector in the same location. I connected it to a set of wires in the nacelle that were switched by the key. Now, having reviewed this thread, I will be changing that one out for a USB style connector. My question is, many adapters connect to battery so you always have power to the USB. Are you better having the power switched or on all of the time? Chances are, you will not have anything connected while you are away from the bike so there is only a small chance you will run down the battery from parasitic loses.

 

I am switching stereos out to a Rockford Fosgate and at the same time swapping my cig lighter style acc port for a RF USB port which plugs into the stereo. I'd like to move the oem accessory port over to the other side of the fairing. But iirc there is no boss to drill a hole through on that side. Still not sure how to make this work, don't want to fubar the fairing up for sure but do want this to end up looking close to oem.

 

I used the fender tip light circuit for power. When looking into the nacelle its on the left (right side of bike) O/W & BK wires if I remember correctly.

 

That's how my 2010 is set up. Here's my '18, basically the same way: