Problem found in 1986 560SEL
 

I posted earlier about my problem with the temperature sensor aspirator blower (on top of the right side heat duct behind the glove box) running all the time - even with the key off! Further investigation found the mono valve on and when I unplugged the R side on the climate control several things clunked. Needless to say I also found the battery always going dead. After much skull work the problem was the group of leads from the climate control stuff (aspiraor, mono valve, etc) was connected to an always hot point in the fuse box and not to fuse #5 ckt 15.

An insidious, and borderline nefarious, defect. Do you blame the PO for this?

Well......
 

The PO probably knew something was wrong hence the great deal I got on it. He did give me a note about the wire being moved from fuse #17 (holder bad) to #19 on the same circuit. But whoever did the deed probably thought they were doing it right since the color codes in the manual are wrong. In the manual they are labeled rt/vi (red and violet) but examining the wires in the harness where they connect to the gadgets they are black with red stripe. When I pulled the fuse block up and looked under it I found a group of red wires on #5 and the group of black on the next connection up.