I have a 21 that I've had for 2.5 years about, and I've had it do something to me a couple of random times, that I can't reproduce, making it difficult to get anything done about it. Basically, air stops blowing out of the vents regardless of whether the system is set at max or not. However, I can hear the fan blowing under the dash. The 2 times it happened were while I was on my way back to Tyler from Dallas. I messed with the controls the whole way trying to find something that might "trick" it into working again. I stopped for about 20 minutes at one point and left it powered off, and that didn't fix it either. Sitting over night fixed it though.

Anyone had anything like this happen to them? My guess is a door related to the internal air direction getting stuck closed or something. I mentioned it to the dealer, but they more or less told me there wasn't much they could do if until they saw it in action.

 

Probably the blend door. I’ve read numerous posts about them and my impression is that they’re a finicky design…

I haven’t had the issue, but the first thing I’d try is to command max airflow, put passenger HVAC to max temp, driver to minimum to see if that extreme would force the system to wake up and function properly.

 

Im pretty sure i tried that combo at one point without any luck.

 

Pretty common problem — the temp sensor in the evaporator core is defective, allowing the evap core to freeze up and block air flow. Fix is replacing the evaporator— requires removing the entire dash. Make sure you drive directly to your dealer while it is frozen, and don’t shut the truck or A/C off until they verthe issue. Should be a warranty repair.

 

Man that's gonna be tricky, the only times it's happened is when I'm driving it for an extended period on the weekends and not even in town. That makes perfect sense though, the only 2 times it happened were when I was in it all day running the AC and sitting overnight made it start working again.

 

See this thread: https://www.f150forum.com/f129/c-int...522428/index2/

 

Yes its a tricky one, happened to me once driving in high humidity and it froze, stopped for a coffee and it was fine hasn't happened since. I know it will return this summer, but the dash teardown is extreme.

 

A common enough occurrence, as you will see in the other thread. And a difficult problem to get repaired since (1) many dealers want to see the problem in action and (2) at least some repair attempts do not cure the problem.