Vacum wipers NEVER work together....one goes one speed and the other goes its own speed...Usually one fast and one slow (slow being the drivers side of course) But after a few mins you get use to it. So if your running two electrics and one is slightly faster than the other after a min or two you wont notice because your to busy trying to stay on the road with NDT tires and the drip from under the windshield that is droping on your right foot soaking your shoes has made you forget all about the wipers being at different speeds....lol