Since both wiper arms stopped, and you can hear the motor run, it sounds like the linkage is disconnected at a ball and socket joint. You will find that you can move one arm and both will move together.
When only one arm stops moving, it is usually a loose 15 mm nut on the arm pivot. Just lift the plastic cover at the base of the arm. It will snap up revealing the nut that must be tightened.
Less common is a pressed-on linkage arm that falls off the pivot. The assembly must be removed for this repair. The arm is tapped back onto the splined shaft, then a light tack weld will prevent it from coming off again. This will also cause only one arm to stop moving, and moving one arm will not cause the other one to move.
Friday, December 30th, 2016 AT 3:04 PM