I would maybe ohm out the motor leads, you could also swap the x and y amps around to check to see if it is the amp or motor. From the Haas manual---"161 X AXIS DRIVE FAULT - Current in X servo motor beyond limit. Possibly caused by a stalled or overloaded
motor. The servos are turned off. Can be caused by running the axis into a mechanical stop, a short in the
motor, or a short of one motor lead to ground"