not to hijack the thread but i am having a similar problem in an 07 suburban. air only blows really cold when the recirculate button is pressed. Everytime i get in and crank up the car i have to press the button to turn the recirc on for the air to get cold.
there is an electric motor mounted to the a/c box called the blend door actuator.
On that actuator is a plastic gear that connects to another big gear on the outside of the box.
Crawl under the dash on the drivers side and look straight up(as close to the center console as possible0 and you will see it.
Reach up and pull the gears back together and they will work again.