I would suspect the control unit itself...if not operational, the proper vents do not open as intended.

But the cheap first tip is to check your fuses...

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2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car