If it's like the 2008 motor, if you can move the mirror by hand, the "slip rings" in the gears are broken.
Mine had a metal ring that I think was supposed to allow the gear to slip if it was bound up. Mine had part of the plastic broken. I took a soldering iron on low (550 F, IIRC) and melted the inner ring to the outer gear to fuse them together. One worked, the other gear slipped again. Since the broken gear only moved it up and down, I haven't bothered to go back in to repair it. I put this on my driver's side, so I still have reverse mirror dip on the passenger side.
I've seen new motors for $80 online. Dealer price is about twice that. :- /