Community Alumni
Apr 12, 2016If I remember correctly, it has to do with where the vents get air from. The driver's side vents get air mostly from the lower half of the evaporator while the passenger side mostly gets air from the upper half of the evaporator. When the refrigerant is low there's enough to absorb the heat at the bottom where it enters the evaporator coil, but it's mostly vaporized before it reaches the upper section.
The blend door issues mostly affect the vents unilaterally. All vents will blow hot or cold, you can only get fresh air or recirculated air through the vents, or you'll loose a set of vents completely (defrost, dash, floor).
