A8 Hybrid Headlights Going Rogue: Switch vs Fuse Issue

Had the same issue on my 2016 A6 Hybrid. The unusual activation of headlights and dashboard lights was initially thought to be just a faulty headlight switch, but diagnostic testing revealed a more complex problem. The root cause turned out to be corroded connections in the main fuse box, combined with a failing multifunction car switch module. Water had seeped into the electrical connections over time, causing intermittent electrical signals. The repair required: Complete cleaning of fuse box connections, Replacement of the multifunction switch assembly, Reprogramming of the lighting control module This was definitely a serious electrical issue that needed immediate attention, as it could have led to complete lighting system failure or even electrical shorts. The repair took two full days at the shop. For your A8, I suggest having the entire lighting control system properly diagnosed rather than just replacing parts. The error codes stored in your system should point to whether its a simple switch issue or something more extensive in the electrical system. Start by having the fuse box connections checked first, then move on to testing the headlight switch if no issues are found there.

Thanks for sharing your experience. My A8 had similar symptoms last year with the tail lights acting up and the dimmer switch going crazy. The electrical problem turned out to be more than just a faulty light switch, they found corrosion in multiple connectors. Mind sharing what the total repair cost was in your case? Mine came to 780 Euro including parts and labor. Just curious if you had any other electrical issues pop up since the repair was done?

My repair ended up being much simpler than initially feared. After taking it to an electrical specialist, they found the car switch issue was isolated to a faulty connection in the headlight switch assembly. The unusual activation of dashboard lights and headlights completely stopped after they fixed the loose cable connection. Total cost came to 95 Euro for the repair, which was just labor since no parts needed replacement. Much better outcome than expected, especially compared to your situation with multiple corroded connectors. No electrical problems since the fix was done 8 months ago. The specialist mentioned regular inspection of electrical connections can prevent similar issues. The light switch works perfectly now, no more unusual activations or error codes in the system. Your repair cost of 780 Euro makes sense given the extensive corrosion damage you described. Seems you had a much more complex electrical problem to resolve.

Thanks everyone for the helpful insights. Wanted to share how my situation turned out. Finally took it to an electrical specialist who found issues beyond just the headlight switch. The fuse box had significant corrosion and several wiring harnesses needed replacement. The repair took 3 days and cost 940 Euro total: New multifunction car switch assembly, Fuse box cleanup and protection, Wiring harness replacement, Labor costs for electrical diagnosis and repair All dashboard lights and switches work perfectly now. No more unusual activations or error codes. The specialist also applied a protective coating to prevent future corrosion in the electrical connections. Much better experience than with my previous mechanic who missed these underlying issues. Lesson learned, electrical problems often need a proper specialist diagnosis rather than just replacing the obvious parts. The higher cost was worth it for a complete fix.