My 2012 F-150 Crew cab with dual climate control recently stopped heating on the driver side vents. In non-dual control, the temp control governs the heat on the passenger side, but remains cold on the driver side. Cooling works properly on both sides, both modes (single and dual). Any thoughts on the problem? I've read much about the Blend Door Motor, but I don't want to dive into that before diagnosing the real problem.

 

I have the same problem...