Trailer light wiring help

Replacing the cheap plastic lights on my tractor supply trailer with some nice metal box and flush mount trailer lights. Can’t seem to get them to work. Suggestions on which wire goes where?

 

I’m guessing White is ground and you need to screw it to the body because of the eyelet on it.

red is likely Break and Black running.
Those colors aren’t used for standard trailer wiring. Brown is usually running light and yellow/green are turn...but it’s been a while since I’ve wired a trailer.

 

Try:

https://www.etrailer.com/faq-wiring.aspx

I would use an ohmmeter to verify connections.

 

Take the loose light up to your truck battery and figure out which is the ground/brake/running

 

Yeah white is ground. I grounded it to a bare metal spot on the light box. I got them to work but only as turn signals. Ideas? I have no running lights

Edit: Think I fixed this issues. I had black hooked to yellow. Gonna reverse it and see

 

And thanks for this idea. Didn’t think of this