Looks like Carson357 may have hit the nail on the head. I popped by a local shop today to get the system charged, and it was showing proper pressure on the refrigerant lines. However, it behaved very badly for the tech -- the driver's side vents were blowing out HEAT, and the passenger side was cool.

So...where to now? I'll run some searches on "duovalve." Is this something I can fix on my own, or am I about to be facing a huge dealer bill? Thanks for any tips!

Cheers, John

__________________
'98 E300TD (W210) | Sold 6/09 with 205k and counting
'04 VW Touareg V10TDI