My wipers are very weak....sometimes they freeze up, but are slow and weak overall. Do I need a new wiper motor?

 

And could also be the wiper transmissions or linkage. Even such things as the connectors to the switch and motor having bad contact. It could be the mechanism in the motor assembly and not the motor. If you remove the motor make sure the wipers move freely.

 

So if I remove the motor, the wipers should move freely.....what if they DON'T?

 

Try hitting the motor using a wood hammer. If it works faster, brushes are mostly worn out.