The issue was that I am an idiot. There was a separate 12v switch for the auto pilot main unit that was not being switched on. It was a little deceiving in that it did
power on though, but as it turns out it was getting 12v via the Sea Talk Cable, coming from the
GPS. Had it not powered on at all I would have suspected
power rather than a faulty drive arm. Anyway I guess the low amp
current coming through the
seatalk cable was enough to engage the drive arm sometimes, but not often.
To correct I removed the 12v wire from the
seatalk connection to the drive unit since I think sea talk is not supposed to have 2 sources of power, then of course turned the 12v power switch on.
Works like a champ now.
Thanks everyone who posted.
-Chris