RS7 Electrical Chaos: Alternator Failure Warning Signs

Had similar electrical issues with my 2018 Audi S7. The symptoms match what you describe, unusual system failures, overvoltage warnings, and weak cold starts. The root cause turned out to be more complex than just the alternator. The voltage regulator was failing intermittently, causing the alternator to overcharge the car battery. This created a chain reaction of electrical issues affecting multiple control modules. The battery itself was damaged from the constant overvoltage condition. The fix required: Testing the complete charging system, Replacing the voltage regulator, Installing a new AGM battery, Performing a full electrical system reset, Recalibrating affected control modules This was a serious electrical issue that needed proper diagnostic equipment to identify. Generic OBD readers often miss the underlying voltage regulation problems. Look for a shop specializing in German car electronics, they should have the right diagnostic tools to properly test the charging system under various loads. The unusual system failures are a clear indicator of electrical issues affecting the car electronics. Get it checked soon, as continued overvoltage can damage more expensive components.

Thanks for that detailed explanation. Your electronic issues sound exactly like what I experienced. The unusual failures from my alternator and overvoltage warnings were really concerning until I got them sorted. Just curious, do you remember roughly what the total repair cost was for fixing all those car electronics? My fix was quite expensive but worth it to prevent further damage to the car ECU and other systems. Also, has everything been working properly since the repair, or have you noticed any lingering issues with the car battery or electrical system?

Had it all fixed last week and absolutely thrilled with the results. The power surge problems and high voltage warnings have completely disappeared. The car electronics are now working flawlessly without any unusual failures. The total repair came to 290 Euro, which covered diagnosing and fixing the car battery that was heavily discharged and damaged from the electrical issue. While it was not a small expense, the peace of mind knowing the charging system is working correctly made it worthwhile. Since the repair, cold starts are strong and all electrical systems are functioning normally. No more warning lights or system malfunctions. The alternator is delivering stable voltage, and the car battery is maintaining proper charge levels. If your symptoms match what I experienced, getting it properly diagnosed and repaired will definitely solve the problems.

Thanks for the guidance. Finally got my car back from the mechanic yesterday. Total cost was around 850 Euro, they replaced the voltage regulator and car battery, plus did a complete diagnostic on all car electronics. Not cheap but definitely worth it. The mechanic found the voltage regulator was completely shot, causing dangerous power surges through the electrical system. This explained all those unusual failures and overvoltage warnings in the car ECU. They also discovered the old battery was damaged beyond repair from all the electrical stress. Took it for a long drive today and everything works perfectly now. No more warning lights, strong cold starts, and all systems functioning normally. Such a relief to have this electrical nightmare behind me. The peace of mind knowing the charging system is fixed properly was worth the cost to protect the expensive electronics.