Yosemitech Y511-A Wiper Problem

With the Y511-A sensors we have (that were purchased about a year ago), whenever you apply 12v to the power wire, the wiper spins continuously in one direction for 5 full revolutions and then “parks” the wiper blade in the home position.  Then it pauses for a few seconds, then it performs the actual back-and-forth cleaning wipe motion (not full rotations).  We had a couple of them malfunction earlier this year and behave as you’re describing:  continuous motor rotation and no measurement data.  We had to ship them back to Yosemitech for repair.  I suspect that there’s something internal that fails to sense when the wiper blade is at the “home” position, so it just keeps spinning until eventually it times out.  You should contact Yosemitech and see what they recommend, but it’s likely that you’ll need to send it to them for repair.