Ash
I'm sure one of the boys on here will be able to point you in the direction of a pictoral thread using the search system.
Simple answer is there is a 99p plastic clip thing that holds the metal bar onto the adjuster flap, once this breaks the system default is full hot air - winters in German can be quite cold !
In order to access this you'll need to remove the glove box lid and liner and look down to the right from the inside the glove box.
If you get stuck look up this document HVAC-01, 944 HVAC Opeation and Malfunction - this details the issue:
"Full Heat at All Temperature Settings (1985.5 and Newer 944s)
On late model 944s (1985.5 and newer), there are several problems that can cause the full heat condition. The first and most common problem is a damper linkage in the driver's side footwell (for left-hand drive cars). Stick your head in the footwell and look up and toward the center console. You should see a small diameter metal rod which rests in a white plastic support and is held in place by a metal retaining clip. On later model 944s, there are two damper linkages instead of one and they are located behind a plastic cover. One of the plastic clips on the linkage may be broken preventing the linkage from operating the damper. When the damper fails to operate, the system fails to full heat. Most German cars are designed to fail this way. It's a safety feature to keep you from freezing in winter. The first picture below shows a linkage that has come loose from the support because the metal clip is broken. The second picture show the linkage properly in place with a new support and clip along with the part numbers for the support and clip
at www.clarks-garage.com
Yours
Chris
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