Not really sure what the official name is but the adjustment **** that switches air flow between floor, mid, winshield...etc on an 03 Express .. well mine is stuck on winshield. Was hoping someone could let me know if that would be the control module itself or the vacuum lines attached to it gone bad. ?? Just bought the vehicle used and noticed the lines were hanging under the passenger side but needed some input before i tear things apart.

 

Anyone? nobody ever have this problem???

 

Mode actuators that determine the air delivery mode? On the 2003 Express, the front ones are vacuum operated. If you see loose vacuum lines, the previous owner must have tried to fix it, albeit unsuccessfully.