Jorge, all of HD's fairing model bikes since at least '97 or so come with a "tour pak harness" as part of the main wiring harness, and it is typically coiled up and stored under the left side cover except on Ultras because it is used for the OEM tour pak lighting, and non-CVO Street Glides because it is used for the rear fender fascia tri-bar LED. I haven't checked for that tour pak harness on the SESG2, but if it's there, it will be an easy way to wire the tour pak lights.
If you don't find the info you want for the Y-harness, it's very easy to use the tour pak harness, and fabbing you own mating connector using the part nos. referenced in my earlier post, specifically: 73103-96BK (used to plug into the bike's TP harness. The wire terminals are 73190-96; three required.
Good luck with your project.
Carl