You could call MCC Tech Support but I doubt they would have a clue. 10 calls would likely result in 10 different answers. I would bet that the docking light wiring would be part of the wiring harness. Maybe someone with your model year coach can provide some information.
If you can't find the wiring or it was not included in the build of your coach you might consider tapping into the backup lights at the tail light assembly. The docking lights on our coach are really pretty lame for backing up and not all that good except to see what is on the right or left side of the coach. I went to Tractor Supply and bought a tractor flood which has a wide pattern and a not very vertical pattern. I tapped into the backup circuit and used it to power a 12v relay. I picked up power from the towing harness. I mounted the flood just above the hitch assembly, well out of harms way. Since the toad will not be connected when backing it made sense to mount it where I did. Made a world of difference, gobs of light directly behind the coach. Others have mounted twin lights under the rear bumper. Probably much more light but you run the hazard of tearing them off entering a driveway.
Dawn and Mark
06 HR Endeavor 40 PET