If you have a Headwinds light, this is on their website..
ATTENTION BIG DOG OWNERS
ISSUE:
Big Dog Motorcycles with an Electronic Harness Control (EHC) require that the high & low beam headlights draw 5 & 4 amps respectively, if they do not the lights will not function properly (they will flash or pulsate) or may not work at all. If hooking up a relay, the solenoid will not draw enough amps to activate the EHC.
SOLUTION:
Install a relay and add an in-line fuse to the lights in the eyes, and install a 20W resister in-line between the relay & Hi/Lo switch.