Been looking at a 94 C280. Car runs/drives great and looks pretty good. But, the HVAC ducts don't change position. I verified that the little vacuum manifold that is under the cover on the pass side where the electronics boxes are, isn't broken and it's getting vacuum. So what's more likely, bad controller or a broken vacuum source supply line? Anyone have any idea how those lines are run? Or have a vacuum schematic for a 94 C280? Does the controller actually control the vacuum switching or does it control electrical signals that then control solenoids?

And... where are the various pieces and how do you get to them?

Already verified that the fan motor is toast.

Karl M.