[VetteVet]

Get yourself a piece of 12 gauge wire about 5 feet long and connect it to the positive battery terminal. Then pull the left outer headlight plug off and touch the wire end to the tan wire in the plug. Your right outer headlight should come on. Then touch the light green wire and the two bright lights and the left outer light should come on. If the light grounds are good and the bulbs are good then your problem is low voltage from the headlight switch. The blue wire to the dimmer swiitch is the power wire so you can also jump between it and the tan or green wire in the connector and your lights should all come on. The outers with the tan wire and all four with the green wire.