AC question

[Hummertech]

The air distribution system in the H2's suck.
GM hasn't published anything regarding this, but I bet they will soon.
All of the electric actuators that move the doors to change the airflow or temperature, make a sweep from one stop to the other every time you start it up so the computer can (find)
what position the actuators are in. It's not uncommon for the actuators to be a little lost or not quite where they need to be. All we can do at the dealer is a quick relearn procedure, and like hum2 says, it works good for a while.