Dirt Bike tail light help?

[LordLosh]

got a 2002 DZR400 with a acerbis tail light it has 3 wires coming off it. GREEN.WHITE,BROWN
On the bike i have 4 wires 2 bigger BLACK ones and a GREY and BLACK/white stripe. I assume the bigger BLACK are for the front and rear brake.
I got power to tail light but can not get it to light up more when brakes are applied no matter what configuration i try
Does the bike have to running maybe?
Unit not working in the 1st place, bought the bike used been fixing it up so i never really checked?
Anyone have any ideas what I'm doing wrong besides me working on it? Thanks

[FZRguy]

Mine works off a pressure switch and only on the rear brake. I just used a multi-meter to figure it out. Been too long to recall details and probably different from your bike anyway.

[FZRguy]

No, the bike does not need to be running. I can take a look when I get home.

[Wrider]

But the key has to be on.