Also, meter the connectors at the cig lighter when the bike is on run. You may also want to sandpaper the spade connectors in case there's some oxidation built up on them.

 

Does cig lighter have power in run position?

 

What headlights are you using? I know some LEDs have been causing interference for guys. Is there any other electronic devices that turn on with the ignition, but don't when you switch to aux? Just spit balling here.

 

Good question, I'll take a look as soon as I can.

 

Cigarette lighters pull a draw if they have been wet or shorted before and wires arent very heavy try the headlight acc. Plug.