I got tired of fuse issues. So, I bought a Die Hard battery pack jump starter that I keep charged up, and keep in my Jeep in case I should have a battery failure on top of a mountain. When towing, I sit the battery pack unit on the floor board of the Jeep (passenger side) and plug the Brake Buddy into that. Works perfect for several hours. I then just charge up the jumper back to 100% for the next day.
http://www.walmart.com/ip/15167318?wmlspartner=wlpa&adid=22222222227019584154&wl0=&wl1=g&wl2=c&wl3=40839232472&wl4=&wl5=pla&wl6=78652621352&veh=sem