Join Date: Mar 2016
Location: Cold Spring Harbor, NY
Mentioned: 3 Post(s)
I think I see your problem. The led is not wired to run both running and brake lights at the same time, although this can be achieved. The description of the light states it can be used as a brake light or turn signals. thus I would assume the black wire is ground, the red wire is positive for one side of the light, and the blue wire is the positive for the other side of the light.
How do you currently have it wired?
If you want both running and brake lights, I can show you how to do this with a pair of diodes and a resistor.