After market LED Tail light on a V7 - Problem.

[Billy]

I'm trying to install an after market LED taillight on my 1TB 2012(2013) v7r.
Its not working, and I'm running out of ideas. Though I might have missed something obvious.

I'm pretty sure I have the wires connected correctly: The Yellow with Green stripe is the brake light, the Yellow is the running light, and he blue is ground.

Its not working, and I have no idea why.
-The orginal tail light still works, so its not a fuse or other short
-The LED light works as an indicator light if I connect the running light to the left indicator, the brake light wire to the right indicator wire, and ground to ground. So the LED light bulbs work (but I have no idea why this configuration works)

Is this a voltage issue? Or something obvious I'm not aware of?

[SportsterDoc]

LEDs are polarity sensitive.
If the unit (combo with turns???) has an LED wired in reverse, it will not illuminate.
That may be the issue.

The factory V7 II schematic shows
B-blue
N-black
Bi-white
to tail/stop

and
G-yellow
B-blue

to license plate light

[Murray]

LEDs are polarity sensitive.
If the unit (combo with turns???) has an LED wired in reverse, it will not illuminate.
That may be the issue.

This check that the sense wires provide power and are not earth switched and check your ground is actually ground.

[Billy]

I have tried all combinations, and no go.

It is only a red tail light (brake and running light) not indicators by the way.
I only connected it to the indicator wires to test if the LED bulbs actually worked and hadn't blown.

Pretty sure dark blue is ground on this model (light blue and red are the indicators, yellow and green/yellow are the brake/running lights).

[Murray]

Pretty sure dark blue is ground on this model (light blue and red are the indicators, yellow and green/yellow are the brake/running lights).

Got a multimeter or test lamp?

[SportsterDoc]

Got a multimeter or test lamp?

+1 and/or post data on the light or a link to it.

[Billy]

Got a multimeter or test lamp?

I don't have one unfortunately but I'll go get one. Back soon

Sent from my SM-G935F using Tapatalk

[Billy]

Tested with multimeter: live wire is close to 12v, and the ground wire is grounding properly. Test Light is working.

Have I missed something obvious like installing a resister? I've tried two LED brake lights now, and neither of them work (connected directly to the wires).
Maybe they're not supposed to handle 12v directly and I've blown both of them? But then one of them works when connected to the indicator wires, so maybe not.

Anyone ever installed an aftermarket LED brake light?
I have no idea what else to test now.

[Kiwi_Roy]

Green /Yellow is a ground colour in many parts of the world.
LED bulbs normally operate on about 3 Volts so there should be resistors inside there somewhere.

Can you give us a part No or something to go on?

[Old Jock]

According to Carl's diagram for the V7 you are quite correct on you interpretation of the wiring

It does not look like any trickery in the circuit

As mentioned polarity is certainly an issue but it should not be if it's an LED replacement for a bulb.

I ASS-ume no form of canbus on these bikes

Sorry no help just some confirmations

[Billy]

-=SOLVED=-

Not a particularly satisfying solution I'm afraid, but solved.

Both tail-lights were faulty. Unbelievable. I tried a third, and it all worked. Cheap tail-lights -- never again (though one of them came from a site many people here shop from). Had to be - the multimeter
suggested the outputs were fine.

Well, now I have a new multimeter to play with, and more knowledge of motorcycle electrical systems.

So thank you all for your replies! Though I feel stupid.

[SportsterDoc]

-=SOLVED=-

Not a particularly satisfying solution I'm afraid, but solved.

Both tail-lights were faulty. Unbelievable. I tried a third, and it all worked.

For most electrical issues, a voltmeter/ohmmeter are indispensable.
Now you can check your battery voltage, etc.

[redhawk47]

Glad you figured it out. If the third unit dies, which may happen considering the quality of the first two:
I installed a Sylvania LED bulb in my OEM unit. A bit brighter than the incandescent bulb, and should last forever. Get the bulb with the red LED.

[Kiwi_Roy]

I buy hundreds of bulbs from Superbright
They have a dedicated motorcycle section

https://www.superbrightleds.com

[Zinfan]

For most electrical issues, a voltmeter/ohmmeter are indispensable.
Now you can check your battery voltage, etc.

And most importantly can check the performance of the R/R to see if it is overcharging the battery.  I know the R/R on my 2013 V7 Stone started to do that and I replaced it as have many others.