I have a 12/85 190D, my heat does not work at all.
The pipes leading to, and from the heater core are hot. The heater core itself is hot. All elements of the vacuum actuation function except I am assuming the blend door actuator.
SO I removed the center console, the vent grills, and the glove box to figure out where it was. I see that it sits up inside of a cowling attached to the top of the inside of the dash.

How do I gain access to the blend door and the blend door actuator?
All I can see without taking the entire dash out is the shaft coming up from behind the heater core, and it's support truss as illustrated in the picture below....













I need to access #37.

I'm replacing the dash soon anyway, I am half tempted to just cut a damn square out of the dash.

anybody want to take a stab

Everybody may be sitting here like me reading this shaking their head not wanting to break the news to you.

One of the worst jobs to have to do on these cars is to change out these blend door actuators. The dash has to come out.

__________________
Jim

Aw heck