About a month ago I installed the 1714 Hi Performance tune in my XLT. I live in Dallas and its been hot forever so I had kept the a/c on all the time. Well about 2 weeks ago, Ii left for work and it was a little cool so I turned the temp gauge to about mid range. The air stayed cool, but the engine temp gauge is at normal operating temp. I turned it all the way to full heat. Air blew cold as could be all the way to work. Got to work early enough to reprogram to Performance Tow tuning. Started the truck, air hot as could be. At lunch I reprogrammed the Hi Perf Tune and it now works properly. Anyone else have a similar problem?

 

Like the defroster does with a/c by cycleing it while on . i cycle my temp adjust also thru the summer monthes to keep it free . Don't believe tuner gave you any probs with heat controls.