1989 Porsche 944 Air conditioning and fresh air blows very

I have an 89 Porsche 944. The other day as I was enjoying my A/C on a very hot day, the air through the vents, started blowing hot air! Hotter than outside air! I closed the vents and turned on the recirculation button. That made it bearable but not cured! By morning, my new battery was dead! I had the battery checked and I have a half an amp draw on the battery. I was told that it is probably a clip that holds the rod that controls the flaps inside the air box and now the rod is stuck. This would explain all issues but I cant find the area that the clips should be in to even see if that is it, I have bought a complete used airbox that is being shipped to me now but would like to know if there could be something else that I may be able to fix? Can someone help me asap please!!!! Thank you, Sean