So I started having issues where the slide wouldn't move at all. I was having to go under the RV and use the manual override to put the slide in or out. ( Page 5 https://www.granddesignrv.com/sites/...ting-Guide.pdf
I error code I was getting on the 13398-C2 motor controller was 1 green and 9 red blinks, motor 1 hall effect sender. Strangely, no mater what motor was plugged into one the issue remained with motor 1. Lippert support told me the motor that finished last on the extend was the one I needed to look at, and that was the rear motor. I thought it must be the controller since it complained about the hall effect on motor 1 no matter what motor was plugged in.
I ordered a motor from Amazon (287298 500 to 1, however I ordered the novoparts one, it was cheaper than the lippert one at the time $125 vs 200).
I also ordered a controller from Ebay (HOWEVER, the controller for my overhead bed is the same controller, had I been thinking I would have used that for my testing and saved $160 bucks.)
I also ordered 2 30' power harnesses from Amazon, figuring I could use them to figure a lot of stuff out and bypass the system if needed.
In the end, it wasn't the motor. Nor was it the controller. It was the shoddy installation of the motor harness to the front of the slide. Instead of drilling a hole, or running it correctly, it was run between the floor and the wall of the RV, probably before they were assembled together. Over time the wall had pinched the wire and it created a intermittent issue.
I also found an issue where the front slide motor coupler was somehow defective, not allowing the motor the recess all the way into the coupler to ensure the motor housing didn't spin and precluding the use of the motor retention screw. A new coupler fixed that issue.
In the end I did replace the rear motor with the new one I bought. Its so hard to get to because of the design of the 34J, once it was in I wasn't going to take it out again if I could avoid it.
I actually bought 2 motors, and one of them had a short in the wiring, again intermittent. I was holding the motor while running a test (off of the RV) and it would just stop if I wiggled it. Investing in the two motor harness cables was a big life saver for trouble shooting, as this would have driven me nuts.