I just finished this mod on my Vulcan 900 Classic. Great idea Seawolf!
I did the two level running/brake light variant that Seawolf described in Post #25
I used a 270 ohm resistor (since I had a pack intended for the fuel gage fix) and it works fine with excellent variation between the bright & dim levels.
For those that may be interested in doing this mod, but aren't electronics experts, you want a diode labeled as "blocking or "rectifying".
Do not use a "Zener" or "breakdown" diode
as these have a different purpose.
I recommend using a 1N5817
since these have a very low forward voltage (0.45V) leaving the maximum remaining voltage for the brightest possible high (brake) intensity.
Don't forget, diodes are directional, so it won’t work if you install it backwards.
This eBay listing
has a whole meter (enough for 5 of these mods) of the LED strip for $5.99 shipped.
You can also get 10 packs of resistors and diodes and meters of shrink tubing for $0.99 shipped on eBay, so get a couple friends together and you can do this mod for a couple bucks per person.
BTW, I was never able to get the 1156 socket out of the housing, so I had to drill a small hole in the bottom and run the wiring underneath. Not as elegant as I hoped, but not that big of a deal.