Audi S5 Light Switch Failure Causing Multiple Issues

Had a similar issue with my 2012 Audi A5. The intermittent lighting problems started with flickering dashboard lights, then the headlight switch began failing. The dimmer switch would sometimes not respond, and the headlights would out of nowhere switch between high and low beams. The electrical problem turned out to be more than just a faulty switch. The main headlight switch wiring harness had deteriorated connection points, and there was corrosion at the plug terminals. The tail lights were also affected due to the shared circuit. The repair required: Replacing the complete headlight switch assembly, Installing a new dimmer switch, Repairing the wiring harness, Cleaning all electrical connections This was a serious electrical issue that could have led to complete lighting failure if left unaddressed. The diagnostic system showed multiple error codes related to the lighting circuit. Would recommend having a qualified shop perform a full electrical diagnostic rather than just replacing parts. Poor connections can cause similar symptoms to a bad switch, and its important to identify the root cause.

Thanks for sharing your experience. I had almost identical problems with my S5 recently. The dimmer switch was acting up and the fuse box showed multiple issues when scanned. My headlight switch was also going bad, causing unusual flickering. Did you ever get these electrical problems completely fixed? Just curious about the final cost of your repair and if you had any recurring issues afterward. Mine has been running fine for about 2 months now, but Im always worried these electrical gremlins might come back.

Thanks for asking about the follow-up. The automotive switch problems were completely resolved after taking it to a specialist. The root cause was identified as a faulty light switch with damaged cable connections, which was causing the erratic behavior in both the headlights and tail lights. The total repair cost came to 95 Euro, which covered fixing the defective plug connection and testing the entire car lighting system. Since the repair was completed six months ago, the electrical problem hasn't returned. The dashboard lights, headlights, and all other lighting components are working perfectly now. If your car has been running fine for two months, the repair was likely done correctly. These car switch issues rarely come back when properly fixed. The key was finding and addressing the root cause rather than just replacing parts. Modern car lighting systems are quite reliable once electrical connection problems are properly resolved. Just keep an eye on your warning lights and error codes, but you should be good to go if everything has been stable for this long.

Here's my story with the mechanic. After reading the replies, I took my S5 to a specialist who actually knew Audis well. The electrical problem turned out to be exactly what others described, bad connections in the fuse box and a failing dimmer switch. The repair process was straightforward. They first ran a complete diagnostic on the car lighting system, which showed multiple fault codes. The mechanic found corroded terminals in the headlight switch and damaged wiring that was causing the flickering. Total cost came to 280 Euro for: New headlight switch, Wiring repair, System diagnostic, Labor It's been running perfectly for 2 months now. No more unusual dashboard lights, no flickering headlights, and all error codes are cleared. The shop even threw in a free follow-up check after 2 weeks to make sure everything was still working properly. Really glad I asked here first, saved me from getting overcharged at my regular shop. Definitely worth finding a specialist for these kinds of electrical issues.