You may have put it back together wrong in regards to the placement of the wipers.
Do you see that set of leaf switches? And that post that sticks up off the ratchet wheel? Normally, that post should move around until it comes in contact with the switch. If you look at the photo in IPDB, you can see the post comes around from the left and rests on the post. More than likely, this is shown in reset position (Ball 1).
See if opening that switch stops the stepping. If so, you may need to orient the wiper differently on the other side.
Hitting the Reset Coil (the shorter one on top) should cause the wheel to zip all the way back to resting on the leaf switch. the larger coil steps it up one tooth with each ball.