Golf Recycle function problem
 

Hi, I was wondering if anybody could guide me with this problem, I have a 1998 GOLF and for a couple of days now the "recycle" button has stopped working. That is, the air is always taken from outside, and not from the cabin itself, making all street smells come into the cabin all the time. I have located the air intake fan at the passenger side of the engine (at the back) and it is always on. I imagine that what is not working is some type of hatch that must "decide" where the air comes from. is this so? Is it easy to fix?

Thanks,

Peter