AC Blows only Hot in 996

[88carrera]

I have a 2003 996 Carrera in which the AC abruptly started blowing only hot air, regardless of settings. Not a Freon charge, cabin filter, or compressor problem. I have been told that it is likely that the linkage from the motor to the "blending flap" that controls the mixture of heated to chilled air has broken or slipped off and is allowing only heated air into the mixing area prior to delivery into the cabin.

Here is my problem: Although I have a PET parts diagram, all that it shows for the heating/AC unit is basically a "black box" without any details about what is inside. Therefore, I cannot imagine what the arrangement of the temperature mixing flap and motor linkage to it might be or how I might make a repair, if that is possible. I cannot see up into the unit to know what is going on.

So, here is my request: Can someone with a Bentley manual take a look at the section on heating and air conditioning and let me know if there is anything resembling a picture or diagrams of what is inside of the unit so that I could imagine what would be required to repair the damage that my unit has experienced? The factory repair manual is just as useless as the PET diagrams for this purpose and I hesitate to lay down $150 for the Bentley manual if it cannot address this problem.

I would be very grateful for any help. TIA.