I suspect the regulator. Mine was klunking for a while before it stopped raising the window all the way closed.

A regulator cured everything, except, for a while I had to press the window UP half of the switch to lower the window, and vice-versa.

It was wired backwards... probably by ME, but now, it's all correct.

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My first Mercedes Benz. 4/6/07.

1984 190E (201 024) 2.3L four.