I have a 2008 Chrysler 300C and my air conditioning blows cold air but when the weather is extremely hot it will stop blowing cold air. This can happen at Random. The Freon is up and full no leaks it is like some sensor fails and if you cycle on off the controls some times it will work and sometimes not. Can someone tell me what to check or replace for this?

 

Hard to say without putting gauges on your system.... could be anything from not enough "Freon" ( probably you have R134 or R134A ) to needing to change your dryer or expansion valve or possibly even your compressor wearing out and can't supply in extreme heat...

having a place just read your system with gauges on will help identify the problem and shouldn't cost that much, other than that its a guessing game as there's a few things that would give the effect you're seeing ( listed above )

 

You state that the Freon is "up and full". Do you know that it is not overcharged? The only way to know for sure is to have the system evacuated and then add back in the correct amount.

 

My bad , the coyote is right, could also be too much "Freon" in the system as well...