The rear ac on our 2005 Expy started making a strange noise yesterday. The problem started when the kids accidentally hit the button that changes the air flow from the vents in the roof to the vents in the floor. When they hit the switch again to change the air flow everything seemed to work fine. Then a clunking noise started from the rear passenger side of the interior. It sounds like something is hung up or something. The noise will go away when the airflow is switched to the floor vents but returns when you switch the airflow back to the roof vents. Air flows fine through the rooof but there is a constant clunk, clunk, clunk coming from the rear passenger side. Any idea what is wrong?

 

Those go out easily. It is some type of air exchanger/door back there. Mine was fixed under warranty.