SebaVending

I'm getting an OC (overcurrent) error on a few selections, one on shelf 4, 2 selections on shelf 2. When I turn the machine off and back on the error goes away and the selection will work for a while until the error comes back. Only happening on about 3 particular selections. I have swapped out the motors with known working motors to no avail. Checked the harness that runs from each motor, nothing seems to be pinched snagged or cut. Checked continuity of said harness, no issues there. Also took one of the shelves that's working and swapped it for the shelf that has the issue and the same selection ends up with an OC error. The shelf seems to be seated properly so I do not think it the plug in the back of the shelf. Running out of options other than replacing the board, or replacing the entire harness that runs behind the shelves on the back spine of the machine. Wondering if anyone has had the same problem with these machines. Thanks in advance.