First... check your fuses... take them out... and put new one in. These MB
fuses are notorious for looking okay but in fact corroded and poor contact.
If your control moves the flaps, then most likely the controller itself is
I would start out with fuses before I get into anything else. The W126
climate control system is very simple system so diagnostic is pretty easy.
As for R134a... if you have a pressure gauge, hook up the low side... by the
shock tower... if the static pressure is 90 PSI, then you do have good
Is the air coming out of the vent cold even though you may not feel any air
movement? If so, then you need to focus on the fan motor...