blackoutf150

hi guys i have 2010 F150 3V 4.6L 6R80 Trans. One day I was hauling a big enclosed utility trailer in tow/haul mode and everything was fine, until later that day I wanted to drive home and the truck would not go into tow/haul mode. The light would not go on nor would it tow well. So I figured that maybe the switch in the end of the gearshift lever was bad, so I went to the dealer and ordered another one. I put it on last night and everything works fine, I clicked it on and off 4 or 5 times no big deal. So today I wanted to try it again, and it doesn't work!!! I have plans to haul a trailer up north tomorrow and I don't feel like wrecking my trans shifting back n forth back in forth. Has anybody got any ideas??? Like I said its completely random, here today gone tomorrow. Also shutting the truck off and restarting it remedy the problem. any input would be appreciated. Thanks!