The blend door doesn't direct the air flow other than over the AC or the heater core. If the problem is getting it to blow through the vents, chances are you have a vacuum leak under the dash or the hood. Start by checking that. When checking, start the engine. You may get lucky and hear a hissing sound from where the leaks is located.
Let me know what you find.
Wednesday, June 9th, 2010 AT 9:15 PM