'96 Ram 4x4 Sport: When I accelerate, my A/C switches from where it blows out. It will be blowing from the front vents and then switches to the defrost vents. Does anyone know what is causing this and how to fix?

 

You have a vacuum leak. One thing you could do is to do a search on this forum for "vacuum leak". Lots of people have had this problem (including me), and there have been lots of posts about it. Read through those because people typically posted where they found their various vacuum leaks at, might help you track yours down. That's going to be your biggest problem. Fixing it is usually not too big of a deal once you find it.
Any other symptoms (that can sometime help you locate the leak)?
Good luck, and post back where you find your leak to help others in the future.