I am trying to add some auxillary led brake lights on the back of my 2015 street bob. From the taillights I have 2 sets of wires each containing black, blue, and violet wires. Which wire is the brake light? I called my dealer Route 66 Harley Davidson, they said I would need to purchase a 60 DOLLAR wiring manual.
I said no thanks. Any help appreciated.

 

The easiest answer is to use a test light and depress the brake to find which one is correct. Being that the bike is a run/brake/turn set-up, I would guess the violet wire is your turn/brake wire. There are two sets of wires to run the each side of the bike. The blue should be run and black ground.

 

If you install accessories, perform maintenance, or change the electrical system yourself then you should invest in a service manual with wire diagrams. The $60 is worth it.

Your wires should be the following at the tail light harness:
Black = Ground wire
Blue = Running Lights
Violet = Brake/Turn Indicator Lights

At the rear light harness, but before the tail light harness:
Black = Ground wire
Blue = Running Lights
Violet (Left) or Brown (Right) = Brake/Turn Indicator Lights

The attached picture is for a 2011 Street Bob but it should be similar minus the Tail lamp of course. Notice the yellow with red wire splits at the main harness. One goes to the converter module and one goes directly to the taillamp. This is so the taillamp, which is brake only, can function independently of the turn signal indicators.

The yellow with red wire that goes to the converter module tells the module the brake has been activated. It then sends the brake signal to the violet wire. The module also sends the turn indicator signals down the violet wire. That means the brake light will be solid or flashing depending on the situation.

If you grab the brake light from one of the side tail lights, your auxiliary light will flash when your blinker is on. You want to get the brake light signal from the yellow with red wire in the main harness, before the converter module. That harness will be under your seat. Also, as already mentioned. Get a 12 volt test light from an autoparts store to make sure you get the right wire. The colors mentioned may not be the same for you, but hopefully you get the gist of it.



Good Luck!