Volvo Repair: 2001 V70 passenger side wiper failure, independent volvo repair, move arm

Question
Mark,
I'm driving to work in pouring rain and suddenly the passenger side wiper quits.  When I stopped, it appeared that the wiper was getting some power ( a small quiver at the base), but won't operate normally on any setting.  Driver's side ok at the moment.  Is this something we can repair ourselves by purchasing a wiper motor at an auto parts store, or is something I must have my independent Volvo repair shop fix for several hundred. Never had this happen on any other car I've owned. Thanks.

Answer
  Susan, shut the wipers off, pry up the small plastic cap at the base of the arm where it attaches to the car. Move arm to rest position. Tighten the 10mm nut you see exposed. Push cover back down, wipe!
  9 out of 10 times that's all it is. If not, hit me again and I'll help you with the other possibilities. BTW there is only one motor that drives both wiprs through a series of arms and cams called the wiper transmission. That will be the next place to look.

Merry Christmas,

Mark