NO AIR OUT OF THE VENTS
The switch on the dash has a slide bar on the back side. On mine the rubber that blocks and redirects the vacuum came loose and wadded up not letting it switch off of def. It's not to hard to take apart and reglue the rubber to the slide bar.
Agreed, the line that was broken on my truck was the one that runs to the passengers side across the firewall that feeds into where the blower is.


