hi, the connector is part of the sidelight circuit, it is covered with a 10 amp fuse which is way more than the lights require and for that reason i believe it is an ignition controlled aux power source.

my hot grips and ciggy style gps/phone charger have been connected via a 7.5 fuse to the connector since i got the bike 26 months and 27,000 miles ago and have worked fine with no problems

bernard