I guess what I would do is take the wiper arms off, on the outside, then turn on the electric wiper and watch the action. Make sure the drivers and passenger sides are going both ways correctly. Then turn it off. Put the splined wiper blades on in the park position, and it should work.
If they are not moving right, perhaps you have the wiper arms reversed on the motor. I.E. they are moving the wrong direction.
When you start the wiper from park, the spindles should turn towards the outside of the vehicle. Otherwise, the arms are reversed.
