Wiring a 3rd brake light??

[cobrAA]

What are the 2 wire you need to wire together to install a 3rd brake light??

I know there's the black wire for the ground, but for the power I tought it was the green/yellow and the green/white, but I made a short-circuit and now when I hit the brake pedal, the light isn't ''brigther''.

So which wire are the good one and how can I solve my problem?

[cobrAA]

Just changed the #19 tailight fuses, didn't do anything.when i hit the brake pedal it's not brithger

[Chow]

You need to test which wire in your taillights is your brake light and tap it into that.

[RyanGTS-T]

Yes, follow your brake lights to the driver side rear quarter panel working back from the bulbs. Basically the wire is spliced right about where the shock tower is. My stock GTS-T LED tail light is spliced there before the wire splits up and divides into several lines to each tail light. Then you just have to ground the other wire I guess. I don't remember the ground wire being spliced.