The driver's side windshield wiper arm not working.
Hi, I have seen this before, and the repair is usually pretty simple. The wiper arm drive is a cone, and the wiper arm just slides on to the drive. A nut usually puts pressure on the arm down onto the cone and that is how it locks into the drive. Sometimes the nut comes loose from the back and forth motion of the wipers and the spring tension in the arm pushes it out of the cone. One of our technicians should be able to verify this and properly reinstall your wiper arm.