Look just above your center vents, between the two of them. On this area of the dash you'll see a little 1" by 1" square with vents in it. Attached to this little square, underneath the dash is an L-shaped tube that comes down and goes to the right. Its connected to the house you have pictured by a piece of foam that, over time, disintegrates.

Basically, stick your face in that hole where the glove box should be, look left, and you should see another hose with nothing connected two it. Attach two said hoses with something of an equivalent diameter (foam pipe insulation, rubber hose, etc.) and you're good to go. I bet your climate control will function a lot better with those hoses connected.

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Seth

1984 300D 225K
1985 300D Donor body
1985 300D Turbo 165K. Totaled. Donor Engine. It runs!!!
1980 300SD 311K My New Baby.
1979 BMW 633csi 62K+++? Dead odo