It is a grounding issue. What I did was to soulder a ground wire to the ground of the blub socket inside the turn signal. This is the only way to insure you get a good ground on our bikes. In other words turn the turn signal into a 2 wire signal. If you don't want to do that you'll have to make sure the post of the turn signal finds a good ground. You can do this by soldering a ring terminal on to the bikes ground wire and put it over the screw post of the turn signal post. Tighten the nut over the ring terminal. Check the ground with an Ohm meter from the blub base to the frame. Good Luck
