That fresh air wheel adjusts the amount of fresh (outside air going thru AC evaporator core) compared to that same air going also thru heater core. When the wheel is on red the face vents blow exactly the same air as all the other vents. The more you turn it to blue the more fresh air is mixed to face vents bypassing the heater core.

Clavurion, thanks for confirming flow. So, then it sounds like BMW designed it in as a back up to the system. If, currently I can only have full on heat flowing through the vents and cool down with fresh air, then that would mean I can direct the airflow to Defrost by electrically opening the vents and then when the fuse blows again,usually blows within a minute, the new airflow will include the defrost. Currently no air flows below or above, only through the main dash vents. This past summer the CCM was fixed on 60F, and so the A/C blew ice cold all the time. But when the temp was changed on the CCM it blew the fuse and the A/C would not work. By leaving the CCM on 60 it worked perfectly, ice cold and I could engage n disengage the A/C using the CCM buttons. Cool.