HVAC blend doors non-functional

[454-k10]

Hello everyone. I know this has been asked before but I’m having trouble finding under hood pics of the vacuum circuit. From what I can see on my 1989 Jimmy is manifold vacuum port is capped off. I have a rubber line unhooked laying near the wiper motor. Air is only blowing out the floor vents. I’m wondering if it really is as simple as this line being disconnected. I don’t know why it was unhooked but I figure I would run this by you all before I plugged it in. I don’t think anything would break hooking it back up, but I honestly don’t know.

 

[454-k10]

Also, I have the dash completely pulled apart so I can clean everything under there and install leds and a new stereo. All the wire connections look fairly sound and the vacuum lines appear to be installed and in good condition.