Just a thought, try unhooking it and see what stops working. That might give you an idea what it does. If your break lights are coming on for no reason, something I have found with a few oof my old 1200is, that the wee stop/plug in the breakpedal falls out/to peices, and the brake light switch sticks into the hole and they come on. I used to fix it by taping a small coin over the hole, but I think that finding a new plug is a better fix.