The windshield wider on the driver side of my 2002 avalanche stopped working. When I turn it on it will wipe across the window once and then stop part way across. The other windshield wiper work just fine. What would cause this and how do I fix it.

Look at the base of the wiper arm; there should be a plastic cap. Pop off that cap with a small screwdriver and tighten the nut holding the wiper arm on. Make sure the wipers are completely off and the arm is in the down position.