Whenever i turn my air on, it only works coming out of the defrost vent regardless of where it's set. I've read up and found a common source to be a vacuum leak.
My mechanic looked at it this morning and said that if it was a vacuum leak he would be able to hear it and the engine would run...
I converted my car to air conditioning with an aftermarket kit and it had a cheap plastic vent for the center dash register. I've searched ebay but can't find an original that's worth it. Does anyone have one or know where to find one?