[W126 Coupe] Strange electrical behavior questions

[Josh Allen]

Ok all, I have a couple of strange electrical questions for anyone who 
cares to risk a guess.

This is all in/on an 84 500SEC euro

1st:
My climate control has decided that the high button, as well as Defrost, 
are apparently unnecessary. 
When I select auto, the fan works normally, and quietly.
When I select any mode OTHER than defrost, it works normally.
If I select Defrost or Max speed, though, it thumbs it's nose at me and 
gives me silence.

I've just recently replaced the fuse in the fuse box listed as serving 
the fan, (and replaced it again, with a ceramic insulator fuse, after it 
spit the plastic body one out the side, partially melted)

Is the 30-amp strip fuse serving the full speed circuit alone?  If so, 
that might explain it, though the strip fuse has had a crack all the way 
through it for the whole time I've had the car, and the fan has worked 
up until this week.  (Mostly due to my not being able to find a source 
for the 30-amp fuses, only the 80 and 50 amp ones.)

2nd:
This car came with euro lights on it.   If I jumper power in the fuse 
box to the high beam circuit, the high bulbs work. 
That being said, they do NOT work when selected either with the 
"passing" mode (pulling back on the arm), or when high beam is selected 
by pushing forward and letting it click there.
If set to high, the lights go out completely.

I have not been able to get into the steering column yet to tear the 
light selector switch apart and look for wear in it's contacts, but 
barring any suggestions, I'm leaning that way next, just dreading trying 
to get the wheel off.

3rd:
Related to the prior question:  how are the euro light wipers and 
sprayers supposed to be controlled?  I see a fuse for it, but they don't 
seem to do anything.

4th:
How is the defroster supposed to work?  I can select it, and it 
momentarily gets brighter on the upper position, but nothing seems to 
say that it's working, and it doesn't seem to defrost anything.


Well, that's all that I've come across that I haven't been able to find 
an answer to in digging around in the various forums that I browse, or 
during listening to this list.
Thanks for any ideas, and happy wrenching or driving to all of you!

-Josh Allen