Does the wiper arm move at all? The motor controls both wiper arms via a linkage assembly under the cowl. If one arm is moving properly, than the cause is most likely a linkage that has come undone, might have a nylon bushing worn or just happened to "pop" off. If your mechanically inclined, you can remove the appropiate clips for the cowl, and the arms will also have to be pulled off-which sometimes if difficult. After ward you should be able to visually see where it has come apart. Is it under warranty? If so the dealer will not charge to rectify this. Also another quick check would be to pull on the left arm to see if it moves by hand, this verifys it's not connected to the system.
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