Aftermarket brake light not working. Need help

The difference in grounding is that the oem light is grounded at the bulb housing and the aftermarket light is grounded inside the bulb area only on a small metal piece (not the whole bulb housing). Hmmm, solder?

Okay, looking at the KZ wiring diagram again, Black and Red are your filament power leads, and Yellow/Blk is your ground. Black is your brake filament and Red is your taillight filament. I noticed that Dime City said they get these taillights and sandblast the chrome off of them and then powdercoat them black.

1. Verify you're wired up correctly based on the above info.
2. If you are wired up correctly or you get it wired correctly and it's still a little dim, grind off some of the powdercoating where the taillight bracket contacts the bike and make a ground path there.

I think we are close here.

Read below..

Problem solved!! Turns out that the light was wired correctly, excepted when it was assembled the black and red wires were soldered in the opposite sides. So the black was positive while red was ground. Light works perfect now. I didn't try this to begin with because I don't like wiring things backwards out of fear of burning something up. Thank you guys for the help, I am learning more.

Congrats!
I'm going to go ride mine now.
:woohoo: