I’m not the only one I guess but I was also told the only the dealer techs know about doing it and supposedly not know to general public or owners. Not sure how true it is since the last guys comments about guys who only know how to put fuel in the truck. HahahaLot's of Youtube videos out there that probably show it better than can be explained. Just search for "Grid heater killer bolt" or something similar. It's basically just grabbing the wire that attaches to the grid heater connection and giving it a wiggle/jiggle. If it feels loose, best stop driving it and get it checked out.