Sometimes when I'm running my a/c, I notice that the air almost starts to gradually stop flowing out of the vents, and turning the fan to high doesn't get much more air flow, and it sounds plugged. Air IS NOT coming out the defrost or floor, so I don't think it'* the flappers changing position. The air that does barely come out is cold like it'* supposed to be.
What I do is hit the a/c switch to turn it off, and keep the fan on high. In a few moments, air starts flowing out the vents like it'* supposed to, then hit the a/c switch again and every thing is fine. On a 2 hour trip, I might have to do this 4-5 times.
I think the coil is freezing up. Is there any fix?

I did have a hose replace last summer and the system checked, I told them what was happening, and they said everything is working up to specs.

I believe there is a sensor that is supposed to keep the coil from freezing. AC guys?

I think your talking about the high pressure switch. I would suggest taking the car to someone that at least has a real set of gauges. If the high side pressure is too high it will do just what your saying it does. There may be a block in the system, maybe a )-Tube.

Good luck,
Sellncars

I don't know if GM uses a similar system as Chrysler, but when I had that same problem on my Concorde they replaced a temperature probe that checks the temperature of the evaporator to keep the thing from freezing up. As I recall, it was a relatively inexpensive fix.