All,
I have a 1974 450SL that I'm driving and fixing, fixing and driving. The center dash controls seem odd, and as I'm trying to install a stereo system I really need to know what's so with them. I haven't found a configuration like this described in any documentation I have. (I'm waiting for the service CD from Mercedes; they said they were doing up a new one, so it would be delayed.)
The layout is like this: on each side, there are the usual up/down sliders for temp and airflow. In between, in the left upper quadrant is a knob to control the blower fan, which works fine. In the right upper quadrant is an odd control that is marked for the cruise control; all the docs I have state the cruise control controls are on the turn signal arm. In the right lower quadrant is a knob marked with two speaker outlines, and since my car has speakers in the dash AND behind the seats, I assume it's some sort of fader; the car had an original AM/FM/cassette (in questionable condition). The left lower quadrant holds the control that really mystifies me: it's a knob that says "Fresh Air" above it and "Inside" below it, with a centerline and a zero character to the left. The actual knob is broken off, and there is a bulb in the erstwhile control's shaft.
Does this sound familiar? Do I have a "grey market" car, or just some custom control setup? Or do I just have crappy documentation for 450s? I'd be most grateful for any guidance you can offer. TIA -- Ian