Can anyone lend me some knowledge? Here’s the problem I’m trying to resolve.

i have a pair of Rizoma rear turn signals. 4 wire.

Black (ground)
white (running light)
red (brake light)
green (yellow turn signal light)

Now coming off the 2018 fat bob I have 4 wires going into a 3 wire plug. However the 4 wires are:

ground
running light
brake light (only)
turn signal light —-however this same wire activates the turn signal flasher, but also the brake light. Turn signal over rides the brake light on this wire.

So i need to find a way to hook up the green turn signal wire on the Rizoma to a turn signal only wire off the Harley. I tried connecting to the purple wire on the front turn signal, to see if it would get the rear signal to flash.. but nothing. Not sure why it isn’t working.

Thanks for any insight or help in advance...

 

Ok so have been studying electrical diagrams etc and I think a solution to connect 3 wire to a 4 wire run/brake/turn signal would be:




ground to ground

running light to running light

split the purple turn signal/brake wire in two. One end go directly to the turn signal wire. The other wire in diode in line then continue to the brake light.

Does this sound correct?

 

if i am following correctly, if you split the wire and add a diode, it will not work. the diode is a one way valve so to speak so if inline, even though split, it sees one wire or voltage source.
i would have to see if i have the schematic. if i have the info, will look but without it i will throw this out. if you find the source be it a tsm or like, find the out put wire for each side and connect to there.

 

Thanks for replaying. I tried the diode and it did not work, as you stated.

Seems my only option is to find a dedicated turn signal wire OR possibly have Harley reprogram the BCM. I’d rather find a dedicated turn signal wire.

Any idea why trying to jump off the front turn signal wires aren’t working?

 

Don't use the green. The bike will control the brake/signal power to the red of the new light.

 

I know that I could keep it this way, but prefer to use the new signals as intended with the dedicated “yellow” turn signal flasher (4th wire).

I spoke to Harley yesterday and the technician told me I can change the setting in the BCM.. so it would function as it would on a 2018 low rider. i would rather find a dedicated turn signal wire but that may not be possible

waiting on a call back from the dealership.

 

It doesn't exist. The rear brake and turn signal are using the same wire through the Turn signal control.
Unless you try bringing a wire from the fronts to the rear greens on their respective lights.
This could potentially work as long as the internal connections of the new light aren't connected,
because then the fronts would get bright whenever you hit the brakes.
You'll have to bench test it. Seems like alot of trouble to go through for no reason..

 

Mount the new light, tap a wire to the front turn signal wires and connect them to the greens.
Then a wire to the rear tail light for the brakes to the red wires of the new lights because the existing wires are brake/turn.
You would be abandoning the existing control wires from the turn module.
Worse case, you connect it like I said in post #5.

 

i was able to snake a wire up the backbone and connect the green wire (rear turn) to the purple wire on one of the front turn signals. However when I activate the turn signal, the front side activates but not the rear.
It’s like it’s getting no power off the front purple wire, even though the front one is...

 

If the black, red and white are connected and it's not working then Back to post #5