Q: the rear wiper motor just chatters and won't move

Hello, thank you for writing in. To start, take a good look at the wiper and its linkage. Make sure nothing is obviously broken. If everything looks to be intact, then turn to the motor. There are plastic gears inside that move the wiper, and they can break after weathering for years. Any build up of snow, ice, or extra weight can also break the gears inside. This would match your symptoms exactly. The motor may run and you may hear it, but it may still need to be replaced. It is recommended that you also replace the windshield wiper itself at the same time. For more help resolving the issue, contact our service department to schedule an appointment.