Fresh Air Vent control Adventure

[Doug41]

1986 560SL. The fresh air vent damper is always closed. I am in behind the control panel. attaching to the re-circulation switch is an obvious wire assembly, then an assembly of two tubes feeding into a three tube connector. Pure red tube popped out when I was getting it out, so question is, what hole of the two remaining does this thing go in?

Also, any ideas of why the vents are always closed? I've checked all fuses, and the tubes leading up to the dampers. All look good. The light does npot light on the control when you push it for re-circulation. Back in the area of the dampers is what looks like a wrapped-up relay assembly, but it's hanging loose. I believe previous owner had been back in here for a radio job.

Lastly, while in there, there was an eight inch styrofoam tube that went from the intake on top of teh dashboard to a solid rubber tube behind the glove box. I assume it's not related to my other problem, but it did disintegrate when I touched it, and I'll have to replace it. Is it anything special, or can a peice of hose from a hardware store do the same thing?