buick headlight wiring harness | eBay Buick Headlight Relay Wiring Harness 4 Head Lamp - Extra 2' Longer Pro Grade ** See more like this Headlight Head Light Lamp Wire Wiring Harness Plug Pigtail Connector OEM Pair (Fits: Buick Buick century: I need a wiring diagram for the headlight Dec 11, 2012I need a wiring diagram for the headlight switch and multi function switch for the headlight high and low beams my dimmer switch "I think" is bad but I would like to confirm and diagnose. its always cheaper to find the bad part instead of just tossing parts at it..Welcome to JustAnswer, my name is XXXXX XXXXX I'm here to help get your problem resolved. It sounds like the headlamp switch is bad. At the headla..The yellow wire on the headlamp switch also goes to the daytime running light module which disables the DRL's but nothing related to dimmer. Here i..I am happy to hear your on the right track. I really do not have any suggestions but if you have any questions I am happy to answer. I wish I could..