Y axis problem - steppers dragging

Hi gang. I'm finishing the build of my new, scratch CNC Router. While all other axis function and rotate smoothly, when manually rotating the steppers on the Y axis feel just like they do if the leads are shorted together. When the steppers are disconnected from the wires that lead to the controller, the steppers rotate freely. The controls and the stepper motors are all being moved from one machine that functioned perfectly to this new machine. The only change was the Shapeoko required one set of stepper motor to be flipped due to the steppers being mounted in the gantry side plates whereas the new CNC uses steppers attached to acme screws that drive the gantry. So the twin steppers now are wired in parallel.

Any appreciated.
Thanks.