Clem, you can use the wiring harness supplied with the lights which connect to: the battery, the lights, and the switch, all via the supplied relay. If you'd like, you can attach the battery leads to the OEM optional auxiliary lights plug which is tucked under the tool kit. It's the triangular triple plug. Eastern Beaver has matching plugs, or you may be able to use the female plug cover on the plug to make your own. Another posted that he opted to connect to the square four wire optional grip heater supply which is next to the aux light plug because it is only energized when the engine is running. I emailed Eastern Beaver and he is checking to see if he can acquire a male and female connector for the OEM headlight wiring harness. If he can get me one, I may just make my own adapter to use the headlight circuit so that my Solo LED's will operate in conjunction with my headlight. That would eliminate the need for an additional relay all together. I think that the circuit could handle the load fine since the Solo's are LED and use less than 2 amps total.