Heater Blows Cool Air on 2 Vent Settings
 

Hi Guys,
the E53 was doing the following: When the heater setting is set to:

- The windshield defrost vents: Very hot air
- The foot vents: Very hot air
- The face vents: Warm-ish air from the middle vents but cool air from both the side vents. If we close the side vents, then the cool air gets directed to the middle vents and then they become cool also.
(Obviously, all of this is with the center turn dial set to 3 red dots)

So, I went in to have a look around and noticed that the cable from the center dial with the red/blue dots had come apart from the lever that it is supposed to move forward and backwards. I replaced it and used a very small tie wrap to secure it in place. Issue solved!

Hope this helps you stay warm!