Originally Posted by RFaber

I had this same issue, in my case it was the internal spring, an easy fix. I think the toughest part is removing the mirror cover. I learned from a BMW tech to use a couple credit cards (or BMW gift cards! lol) to push the clips away from their latch points. once i learned that, it was easy! oh and put a protective cloth/towel around the mirror to avoid any scratching!!
I found my limit switches were ok, but the mirror wouldnt sit properly because someone had bumped it. later i determined the notch and tab in the pic were out of position, once i realigned them (simple screwdriver to move it over) it all worked flawlessly again! hope this helps!