Just a few days ago I was changing my spark plugs and I’m 99% sure that’s when I knocked it out of place, but now I can’t figure out where it goes. A/c doesn’t come out of vents, just defrosters.

 

Did you intend to include a photo so we could tell which vacuum line you are referring to? Since you only have HVAC airflow through the defroster vents, it sounds like your flow is set to the failsafe mode and the vacuum hose likely connects either to the firewall or to a section of plastic hose connected to the firewall.

-Rod

 

 

The photo is in your most recent post but did not appear in your original post. I no longer have a Mountaineer to look at for a reference, but having the photo will certainly help someone who has one in their driveway take a look at get back to you.

-Rod