Check your Mono Valve ASAP and your Aux Water Pump. Unplug them both NOW! These fail (freeze up(not weather)and will smoke your ACCU. That smell is your ACCU Unit frying. You will still get defrost air with the monovalve unpluged(you can't turn it off) and the AWP just circulates hot water in traffic and you probably won't even notice the AWP not working.
And why didn't you pop those wipers loose or did you accidentally manage to twist the wipers on? BAD RAYMR, Bad, Bad RAYMR! (been there and done that and have a burnt ACCU to prove it...same model car too.

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1986 Euro 500SEC "RUF" 9:1CR, "Rose"
1985 Euro 500SEC Cabriolet AMG Widebody
1982 Euro 500SEL "Blue"
2001 Texas Heeler (Aussie/Queensland X) "Sulphie",
2012 Queensland Red Heeler "Squeak"
Best dogs I've ever had.