Hi Billie, if you can still hear the motor running when you turn on the windscreen wipers its possible that the socket may have just popped off the ball joint.
You can pop the bolt covers off (where the windscreen wipers are bolted to the car), unscrew the bolts and remove the windscreen wipers. Then take off the plastic cover which should gives you access to the arm, to give you a better idea of whats gone wrong.
I found that the plastic socket had come off the metal ball joint, so went to a local nissan parts dealer and bought a retainer for about 60p and fitted it.
spongejon, February 2009