Deaf1, by now you have made your purchase and installation. For future members let me share how I approach rear lighting. Before beginning RayG is right-on-it H-D could make this simple, we will pay for it regardless. I love LED’s, but face it they are not as bright as bulbs. Now this is my second attempt adding rear light on my serk. The first set melted, reason, too cheep. I begin with a backoff modular, and I found that it would sit perfectly in the tombstone housing. Expose the brake lead and sorter them.
I did want to change the look of the rear with a gaudy add-on or LED’s. I wanted the lighting to have some distance from the tombstone. I purchase the mini lamps from JC Whitney. Every distributor sales this style now. I needed a better bracket that comes off the saddlebag rail. Home Depot sales elbow heavy weight galvanize brackets and with a hacksaw, power drill, and a file fabricate a brace for your lamps. Wire the running light to the running lights. If I remember correctly, the lamps are 35 watts. The housing is metal and has two filters. I could only get one to work and seal the housing. The light is bright and blazes, which makes it annoying, and car driver are always passing me at night.
I have 7 picts
I hope that is not too many