Just wanted to say that I did this mod after adding led turn signals.
I added the four turn signals (two forward, two aft) and got the four-way hazard light blink. Nice to have since the Vulcan does not have flashers. But I could not leave her that way. So I did the mod as described (thanks for the pics) and it worked like a charm.
While I was in there, I left the original t/s on the front but changed the orange lens to a clear one and added a led bulb. I also removed the t/s wire from it (I used that on the led t/s) making it a light bar sort of. With the led t/s above them. Check pic.
Thanks for the mod post, I'm sure it has helped a lot of riders.