When I tried the blower motor on my 86 300e it didn't work. First thing I did was to check the fuse (#12) and the bottom of the fuse holder(?) seems to bel all melted. What could have caused it? I recently changed out the battery.

 

It was just a bad design from Benz, back in those days there was an update that moved the fuse out of the fuse box.

 

So. is it a short somewhere causing too much voltage to flow through that fuse?

 

Probably not, on the early 124's the fuse heats up and melts into the fuse holder. The fix at the time was an externally mounted fuse holder that used a ribbon type fuse. The repair kit is probably still available. I'll check at work and see if I can come up with the part # tommorrow.