Y axis Fails continuosly,

Marty, are you certain the g-shield is actually shorted? I had issues with my Y previously and it ended up being a bad crimp on the wire. Assuming you haven’t done that already I would scrub the entire line from motor to controller looking for any sign of bad crimp, loose wire, broken wire, or wear spot where it could be shorting etc. Have you checked that the pots are adjusted correctly. There are several videos showing these steps you might take a look at.