I got in my 2008 nitro yesterday to go home. Turned on the ac and only a little air was coming out of the vents. I could hear the air blowing somewhere just not out of the vents very much like it should. Everything worked fine this morning but now that it's hot nothing. Also, I was playing with the knob thinking that was it but it didn't change. One thing is when I turned it on to floor it started blasting out of the defrost.