I have a 2017 XL1200C. I have noticed that there is a square gray connector (which I think is the Can Bus connector) coming out from the bottom of the left side cover.
It just hangs there along with the battery charging cable. I took the left side cover off to see if there is a place to store this gray connector, but I could see there isn't any room under the left side cover for this connector to go. So where does this square gray connector get stored, or does it just hang there from the bottom of the left side cover?

 

What Poverty said, it just kinda dangles there... I've tried several times to tuck it back up in there, it just drops back down again.

 

If you look carefully on the underside of the battery tray caddy, you will see the preformed indent that it is supposed to slide onto. A bit of a pain to locate as you have to push the excess wiring from the grey data link connector into the hole that it's wiring comes out of to be able to mount it correctly. Hence why you mostly see it left hanging down.