I have a similar problem with my 350sd. For about a two or three weeks the blower has been making a wierd noise (like the fan was wobbling back & forth) and all the sudden stopped working. I don't think it's the ACC unit because it I can switch it to min and max and while driving down the highway air will come through a little. Also the flaps will still close and open according the ACC setting. I have checked fused and I'm looking for more info on how to take the blower out. I was told it could be the brushes.