Had this happen a couple times in the last month. I have a 54 one way comute to work. Use mostly interstate and use cruise control. The other night while driving home from work had cruise set at or around 75. got up to some slower trafic doing the limit of 70 passing a couple of trucks. I just coasted the cruise down to the speed they cars were in front of me doing for a couple miles then once they got out of my way went o bring it back up to my cruising speed by pushing the set button to accerate to 75. Well as soon as I hit the button cruise shut off. It wold not turn back on trie a few times the next few minutes but it wold not turn back on. After about 10 minutes it started working again. This was the secind time I had this happen in the last month it would quit for about 10 minutes before it would start working again. Its a 05 with the 5.4 and about 350 miles shy of the 100k mark as of right now.

 

Do you possibly have a sticky brake light switch?

 

First place I'ld look is brake light switch adjustment .... right after I made sure my foot wasn't in any way near the pedal.

 

I'll be looking into the brake light switch as a posable cause of the problem. As I keep my feet away from the peddles when using cruise control. Had new brake pads put on the tuck about 5000 miles ago don't know if that has anything to do with anything on it.