Alright, I'm in a little bit of a jam and could use some help. I am in the middle of my chopping project and am stuck with my wiring. I am wiring up a cat eye side mount tail light and I can't get it to work. My turn signals are all rewired and work fine but this tail light is driving me crazy. Right now the housing acts as the ground, and I have the red/yellow (brake light) wired up the red, and the blue (running/license plate light) wired to the black. All wires are hot and when powered up there is no activity. Any ideas would be appreciated!?

...oh and there was a orange/white wire that I capped off (everything I have been reading says you don't need it)

 

did you even solve it? I am having the same problem

 

Sounds like the ground, if you have power to the wires. Try grounding it to something else to see if it works, and check to make sure the manufacturer's ground actually runs to the bulb.