Square rear lights with Factory Five wiring

[Grande]

Hi guys, just helping complete a build on friends cobra roadster. He has the Factory Five wiring harness at rear, with 4 wires, and received new square rear lights, with 3 wires. I have been trying to make these work but cant make sense out of them. Any ideas on how to wire them. Tried Black ground, and powering one the red or white doesnt light them up. Thanks' in advance.

[JJK]

The kit should have come with a converter. It is a black rectangle about 1/2" thick and maybe 2"x3" with a bunch of wire coming out of it. Wiring instructions are posted on FFR website

[Grande]

oh wow,thanks did not realize that, will go to web site and look for it, appreciate it thanks.

[JJK]

check here
https://thefactoryfiveforum.com/showthread.php?35681-Tail-Light-Wiring

or here
https://thefactoryfiveforum.com/showthread.php?38666-Question-about-LED-converter-for-tail-lights-Update-LED-lights-are-all-sorted-THANKS