2003 Expedition Eddie Bauer 5.4 - My AC is cold and blows well at idle, but on acceleration it sounds like it is blowing but no air coming out of vents. If I back off the accelerator I get a blast of cold air that continues until I start accelerating again. Seams to be worse when I am sending air to the rear (which I think is working fine and consistent).

Thanks for any help.

 

Something you can check. Listen for a possible vacuum leak. Engine vacuum is usually highest at idle and when you open the throttle to allow more air into the engine vacuum drops and some things that are controlled by vacuum respond to the lower vacuum.