A few days ago my exhaust brake and tow haul quit working, the next day I tried it and it worked and has worked since then. Today my cruse control stopped working and has not started working again. I'm on a 6k mile cross country trip pulling a 10K 5th wheel, I need these things to work. Can somebody give me a clue as to what's going on. Please help I have checked fuses, they all look good.