I just got an 02 cavalier and found out the headlights only work every once in.a while. When I turn the switch on you can hear the door locks. Also wipers only work when they want ( not sure if related or the motor) changed neg. battery cable thought it might have been it changed switch for headlights and same thing.it was in an accident and air bags deployed. Wouldn't think the air bags would cause anything just wanted to give all details hoping someone could give me an idea where to start...

 

Take voltage meter and Check all of your ground wires