The exhaust brakes on my 2006 Newmar Kountry Star have stopped working. I can activiate the switch however, nothing happens...no downshifting, no light illumination on the dash, no exhaust brakes. It seems to me that this may be an electrical issue. I have checked my fuse panel and was unable to find one that was labeled "auxiliary brake". I would appreciate any suggestions on what the problem may be or where I should look for a blown fuse.