I have made sure to check that the recall was done and it has. Here is my issue:
In the morning, especially when it's cool outside, my cruise works just fine. When my vehicle comes up to temp, it shuts off and won't turn back on. Also, if it is warm outside (say 80 degrees or so) it won't work at all either.

Things I have checked, I ran the self test and don't have any error codes. I have checked to see if the brake has started to sag, and that makes no difference. Any ideas? I have looked thru many forums and have not found this problem anywhere else (as of yet.)

 

Im guessing two things here. The deactivation switch on the master cylinder is bad.

or the more likely, you've got contaminated brake fluid that expands when hot, causing slight pressure on the switch, causing the CC system to turn off

 

Thanks. I'll change that fluid this weekend.

 

99% agree it's the cause.
Been through it already.
Use a switch from Ford not from an after market source.
Good luck.

 

May not be your problem since it seems to be temp related, but these trucks also have a history of a wire rubbing through the insulation and shorting out which causes this exact symptom. I had it on my truck and chased it for weeks until someone told me about the wire issue. The wire in question is in the steering column inside the truck. Remove the covering behind the steering wheel and it's in there. It was very apparent once I got in there as the exposed wire was easy to find…just a thought.