The car is a 1983 200D.

My brake master cylinder has some connector without anything attached - what's it for?



The glow plug relay has this extra wire hacked in that seems to connect to the A/C fan in the front - the other wire goes up under the battery along with one of the A/C tubes:






I've got no idea what the correct wiring should be, but this doesn't seem to be it. The A/C does not work and the large metal tube going down to the compressor is broken completely through.

There is a switch on the upper center of the dash that controls fan function:



However I am not sure it is wired correctly because it has three positions - up, center, and down. Center allows fan/heat to work great, but it only comes through the defrost vents and a little bit through the foot vents, none through the dash vents. If I switch the switch either up or down, the fan sound changes notably and air blows through the dash vents, however I also hear the engine bog down considerably so I believe this means the A/C compressor is getting engaged. How are these controls supposed to work? I'm actually interested in removing the A/C entirely from the vehicle - if it's not there, should there still be some sort of switch for a manual climate control system?

P.S. I'm not sure why the above images don't seem to work but if you right-click them and open them in a new tab/window, they show up.