If the passenger side is working with the harness and you did the ol-swapperroo,check the leads to the drivers side with a volt meter to make sure you are getting 12volts. Make sure the grounds are sanded to bare silver metal. Hopefully you have 2 grounds, one for each headlight ballast. The passenger side has the trigger/old headlight wire to the harness and you know that works.
That means, if the harness is good(ouch!) you should have juice to the other side. Only two wires are the problem.
My drivers side had a flicker at first. I thought WThell,so I swapped ballasts, but at the same time sanded both ground spots on the bumper and the wire ring connects on the leads. I had only scraped the paint with a utility knife blade at first.
Works like a bright-eyed demon now.
