Audi S3 Light Switch Malfunction Causing Tail Light Fails

Had a similar electrical problem in my 2019 Audi RS3. The headlight switch started acting up, with dashboard lights showing unusual errors and tail lights failing intermittently. The root cause turned out to be corroded connector pins in the main lighting control module. Water had seeped into the connection housing over time, creating resistance in the circuit. This caused the system to misread switch positions and fail to activate the lights properly. The repair involved replacing the entire lighting control module assembly and resealing the connection points. It was a serious issue since faulty car lighting can lead to unsafe driving conditions and potential electrical system damage if left unaddressed. Worth checking the connector housing near your headlight switch for signs of moisture or corrosion. Often the issue lies not with the switch itself but with the connecting components. The symptoms match what you describe with the intermittent tail light failures and error codes. These car switch problems typically worsen over time, so addressing it sooner rather than later is advisable. A qualified technician should be able to diagnose whether its the control module or just the connections needing attention.

Thanks for sharing your experience. Good to know about the corroded connectors, definitely matches what I am seeing. The dimmer switch has also started acting weird lately, making me think its all connected to the same issue. Did you remember roughly how much the repair cost for the control module replacement? Also curious if youve had any other electrical gremlins pop up since getting it fixed. Im trying to budget for the worst case and wondering if I should have them check the entire fuse box while they are at it. Hoping to get this sorted before winter when proper lighting becomes even more critical.

Just got back from the mechanic after dealing with similar dimmer switch and tail light issues on my RS3. Happy to report the problem was simpler than expected. The automotive switch system just needed a thorough cleaning and reconnection, no full module replacement required. The total repair came to 95 Euro, mainly for labor to trace and fix the faulty cable connections. The headlight switch and all lighting controls are working perfectly now. Much cheaper than the control module replacement I initially feared would be needed. Cannot stress enough how critical it is to address these electrical gremlins quickly. A properly functioning dashboard lights system is essential for safe driving. In my case, catching it early meant avoiding more extensive damage to the electrical components. The fuse box checkup is a smart idea while they are working on it. My mechanic did a quick inspection of the surrounding electrical components during the repair, which provided good peace of mind that there were no other developing issues.

Thanks for the input. Finally got my car back from the mechanic yesterday. The issue was indeed similar to what others described, moisture had gotten into the car switch housing causing intermittent failures in the tail lights. My repair came to 180 Euro total. They cleaned all the connections, replaced some corroded wiring near the dimmer switch, and sealed everything properly. They also checked the fuse box and found a loose connection which they fixed at no extra charge. The mechanic took time to show me where water had been getting in and recommended some preventive measures. Much better experience than my previous repair shop visit. All the car lighting is working perfectly now, no more unusual error codes or failing tail lights. Worth every cent for the peace of mind, especially with darker days ahead. Thanks again for helping me understand what I was dealing with before heading to the shop. Made it much easier to discuss the problem with the mechanic.