I have a 2008 CTS and I believe the main blend door acuator isnt working do to the fact that all my vents are blowing but when trying to switch where I want the air to blow the air isnt redirecting.The heat works fine,the air works fine and my temperatures change.My question is where would I find the main blend door actuator in order to replace it? What do I have to disassemble? And if anybody has diagrams of the break down of how to get to the actuator that would be greatly appreciated! If I am wrong about it being the acuator I think it is please correct me. Thanks ahead of time!