With AC on low fan only (on high fan all vents blow cold), the drivers side vent and the drivers center vent are blowing hot air. But the passenger side vent and passenger center vent are blowing cold air.

The center vent really seems odd to me, since it I know the air comes from one "big" cavity/tube (I have wedged the flap open), so not sure how it could have two different air temperatures coming from the same central source.

Is it likely something to do with the various pods/flaps? If so, which ones?

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02 E320 Black (198K)
85 300D Blue (147K)
83 300D Blue (299K)
Plus 2 300D Parts Cars
05 ML350 Silver (165K)
02 ML320 White (207K)

Sure helps to know what car...

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Sorry, 83 300D

__________________
02 E320 Black (198K)
85 300D Blue (147K)
83 300D Blue (299K)
Plus 2 300D Parts Cars
05 ML350 Silver (165K)
02 ML320 White (207K)

Center vent blows outside air on every Merc I’ve ever owned.