like legit neon? not led? wow..didn't know people actually used that anymore. It could be, if they are real neon, that they are drawing too much current. when you add on your headlights, its too much to handle and one goes out. neon is a fickle thing, thats why no one uses it for signs and stuff now, its all led. Neon lights require a lot of juice, its possible (and probable) that the original little honda battery can not supply both headlights and neon lights without a high powered alternator.