Hello cbr guys. I just got a new undertail for my f4i from motofairings (not very great quality, i would not recommend) and i need help wiring it together so that i have a running light, break light, and turn signals. I'll post up a few pics so that you can get a better idea of what I'm looking at. So far I've gotten a brake light and turn signal light but I can't get a running light! Any help would be much appreciated!

the wires coming from the undertail:

2 clusters of
1 red
1 white
1 green
1 black

wires from original harness:

brake and running light
2 clusters of
2 green
1 black

turn signals:

left
1 green
1 orange

right
1 blue
1 green

 

connect to the black wire in the pin that has the green and green with yellow stripe.

You should learn to use a voltmeter

 

Did you not get instructions with the undertail. I have no idea which wires correspond to what on that undertail, but the original harness is this. The brake and running light doesnt have 2 green, it has 1 green and one green/yellow. The solid green is your ground. The green/yellow is your brake light. The Black/brown is your running lights. The turn signals are the same with Green being ground, and orange and blue being your positives for those lights. I would imagine on the undertail Black or Green is going to be your ground, and the other three colors will correspond brake,turn,running, however I dont know without a diagram or physically seeing the setup.

 

The undertail didn't come with instructions like I had hoped. But from what you said the harness wires are, I think that I can wire it now. It sounds like you know your stuff jonld. I know nothing of electrical wiring, so this is a big help. I will work on it as soon as I get home from school tomorrow. Thanks a ton for replying guys.
-Mike

 

Any addition help would be awesome!

 

If your brake lights and blinkers are hooked up already like you said, there's only one wire left to hook up besides the black ground wire which you should already have hooked up since your blinkers are working. Should be an easy problem to solve, but come back here if you can't.

 

Despite the great advice you guys gave me, I still cannot get a running light. I plug in the wires that you told me to, I get a turn signal, and I can get a brake light. When I alternate brake and running, I get a dim brake light, which makes sense because the running light would be more dim. But, I did notice that the other bulb to the remaining brake light that I did not remove is not lit while the bike is running. So, I am wondering if my running lights are not working at all, and if that is a possibility, how do I fix this magical problem? I'm sorry guys I wish I could get this fixed so I could stop bothering you...

 

A quick thought: Will my running lights not work because leds are not dual filament bulbs?

 

Did you hook up your ground wires to start with? Will not work properly if the ground isn't hooked up.

And the undertail works off of LED's, so no dual lights.

 

Who makes your undertail? You need to find online directions to hook up because not all undertails are the same and the wire diagrams will be color coded differently. If I knew what the undertail wires went to, I'd be able to tell you the exact wires on the bike to hook in to.