Theres a small cylinder back and to the left of the HU. There are 2 hoses connected to it. I believe the one on the right hand side controls the vents and is easy to reconnect. Try sliding out your HU half way and reach behind. If that is too hard (i have tiny hands). Take the entire HU and go through the opening. Once you take a look you should exactly what I'm talking about and which hose has come out. I hope this helps.
