Not sure about other years, but as for the 15s It works like this, low beam lights on its normal, push fog light button, there on, push button again there off, for low beams. High beams they are on no matter what lol Its like a super high beam. click down to low beam there off, unless you had them on already with lows, then they would stay on. Thats the only down fall is there constantly on with high beams. But thats why we use high beems to see farther rite. It works great!