Please Help Me!!

it may be a long shot but have u checked the ballast resistor it,s a small white porcelean box mounted on fire wall or drivers side fender usually fire wall it has i believe for 68 a single prong plug on either side of the mounting screw this is usually the last thing that anybody looks at but is usually the culprit u can use a jumper wire between the plug ins to test temporarily good luck.and welcome to fabo u will meat a lot of great and knowledgible people here