Driver side windshield wiper arm stopped moving but passenger side works

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Sounds like it just needs a vacation. I think you have a broken wiper transmission or linkage. One wiper is driven by a motor and the other by the linkage. Or it could be the nut that secures the wiper is loose or stripped! Check that out as a first step! Good luck! If you have any other questions, please call us at 877-913-1554! We'll gladly find you a certified RepairPal shop in your area!