I would change the bulb first as there could be a loose connection there. If you determine that the connector or harness is at fault, try contacting Autobahn used smart car parts in El Cajon, CA. and see if they will sell you a harness or connector. Their phone number is: (619) 444-2290. The brown wires are grounds. Trace the ground wires out to make sure they are night where they attach to the chassis.