Wow, I understand that that's a heck of a job. There was one of those "How It's Made" shows on the GW a couple of years ago, and they showed the wiring harness installation.
It's the second thing that goes on.. In fact, they kind of took the harness and installed the frame on it.. It required heating, bending, fitting, and it looked like a lot of work to get it into a bare frame.. Installing it on an already assembled bike looked like it would be a challenge..
Here's the video.. the part you want to see is at the 4:25 mark.