Duke 2 taillight short??

[Yamahardman]

Howdy folks, ive put a led 3 wire light on the back of my duke 2, and when the lights are off the tail light is going full bore, but when i turn the lights on its got nothing. Any ideas? Im terrible at electrical stuff.

Thanks in advance
-mitchell

[Honest Andy]

A 3 wire light usually means 1 wire to earth (-), 1 wire to tail light feed (+), and 1 wire to brake light feed (+).
Check you haven't reversed any of them, and check the instructions (the colours on the new light might not be the same as the old one).
If that doesn't help then post some photos of the light, the bike wires, and the instructions...