RS7 Alternator Failure: Warning Signs and Repair Guide

Having seen similar alternator issues on my RS6 from around the same period, I can share some relevant experience. The symptoms you describe, dimming lights, starting problems, and warning lights, strongly point to a failing alternator, which matches what I encountered. With some experience working on these engines, I initially thought it was just a serpentine belt issue, but it turned out the alternator was completely failing. The car would barely start, even with a new battery installed. The alternator replacement at my regular workshop cost 960 Euro total, including parts and labor. They had to remove several components to access the alternator properly, which is typical for these engines. The repair took about 6 hours to complete. Before proceeding further, could you share: Your RS7 build year, Current mileage, Whether you notice the issues more during cold starts, If the battery warning light stays constant or flickers, Any additional error codes you have This information would help confirm if your situation matches what I encountered and allow me to provide more specific guidance about the alternator replacement process. A proper diagnosis is crucial, while the symptoms point to an alternator issue, having the correct information will ensure you dont replace parts unnecessarily.

Thanks for sharing your experience. My 2023 RS7 had its latest service at 162969 KM. Regarding your questions: the battery warning light stays constant, and the issues are consistent regardless of engine temperature. The alternator issue symptoms started suddenly during normal driving. I checked with my OBD reader and got error codes P0622 and P0562, both related to charging system faults. The serpentine belt looks intact with no visible wear, which further points to the alternator being the core problem. Before considering a full alternator replacement, would it make sense to test the voltage regulator separately? The part is more accessible and could be a cheaper fix if thats the root cause of the charging problems.

Thanks for providing those details. Based on my experience with the same charging system issues in my RS7, I would actually advise against testing just the voltage regulator separately. While it might seem like a cost-saving approach, I learned the hard way that isolated voltage regulator issues are quite rare in these models. When my alternator issue developed, I initially tried the same route, replacing just the voltage regulator. The charging system problems persisted, and I ended up paying for both repairs. The alternator assembly in these cars is designed as an integrated unit, and when the charging system starts failing, its usually the entire alternator that needs replacement. My OBD showed the exact same error codes, P0622 and P0562. These codes, combined with your constant battery warning light and sudden onset of symptoms, mirror my experience exactly. The serpentine belt might look fine, but the alternator issue can develop independently of belt condition. Given the mileage and symptoms, a complete alternator replacement is likely the most reliable fix. The repair costs and time I mentioned earlier should be similar for your case, though prices may have adjusted slightly. The charging system in these models is quite robust when working properly, and a new alternator should resolve all the symptoms youre experiencing, the weak starts, reduced engine power, and electrical issues.

Thank you for the detailed feedback. After hearing about your similar experience with the alternator issues, I think moving forward with a complete alternator replacement makes the most sense. The matching error codes and identical symptoms are too similar to ignore, and I dont want to waste money trying smaller fixes first. The voltage drop symptoms and consistent warning lights match the pattern you described perfectly. Even though testing the voltage regulator alone would be cheaper initially, I see now that its probably not worth the risk of paying twice for repairs. Given the similarities in our situations, I will budget around 1000 Euro for the alternator replacement and plan for the car to be in the shop for a full day. Better to fix it properly now than risk getting stranded with a complete charging system failure. Will schedule the repair next week and make sure they do a full alternator replacement rather than trying any partial fixes. Really helpful to know what the repair process entails and the approximate costs before going in. The starter motor and other car electronics should work properly once the new alternator is installed.