What is a commutator? My friends have said something about it but I‘m not really understanding it.
Commutator That part of a dc motor or generator which serves the dual function, in combination with brushes, of providing an electrical connection between the rotating armature winding and the stationary terminals, and of permitting the reversal of the current in the armature windings. For explanation of the necessity of this function See also Commutation. A commutator (see illustration) is composed of copper bars assembled to form a drumlike cylinder which is concentric with the axis of rotation. Insulation, commonly mica, to provide exceptional mechanical and electrical stability, is placed between commutator bars and between the bars and the shaft. Conducting brushes, commonly carbon, sufficient in size and number to carry the current, are spaced at intervals of 180 electrical degrees about the surface of the commutator and held in contact with the surface of the commutator by spring tension. See also Direct-current generator; Direct-current motor; Electric rotating machinery.
You can get a new wiper arm at the auto parts store.
look at the shaft where the wiper goes onto. see if it,s all chewed up. if it is then it can,t work back and forth. also you have long rods on the wiper motor.check to see if 1 of those popped off.
sounds like the whole left arm does not move while the right one does, right? That means you would tighten the nut at the base of the arm, since you did that, the wiper transmission is bad and you probably need to bring the car in. Especially if you can easily move the left arm when it is not running and the right arm will not move.
