Alfa MiTo Electrical Chaos: Power Surge Warning

I had a very similar issue with my 2014 Alfa Giulietta diesel last winter. With some experience working on car electronics, I can tell you these symptoms match what I went through. Initially thought it was just a weak car battery, but the workshop diagnosed an alternator failure that was causing power surges. These irregular voltage spikes were slowly damaging the battery and other electronic components. The repair cost me 290 Euro and included: Complete alternator diagnostics, Replacement of voltage regulator, New battery installation, System reset and testing Since the fix, all electrical systems have been working perfectly with no more unusual failures or starting issues. To help diagnose your case more precisely, could you share: Current battery voltage readings, Age of alternator, Any warning lights on dashboard, Whether issues occur more during idle or driving, If you notice dimming headlights The MiTo and Giulietta share similar electrical systems, so the root cause might be identical. These overvoltage issues definitely need addressing soon to prevent damage to other electronic components.

Thanks for the insights. Just had my last service at 82324 KM and they did not catch this issue. The voltage readings fluctuate between 12.8V and 15.2V, which seems way too high. No warning lights, but the headlights do flicker occasionally when idling. The alternator is original to the car. The car electronics seem most unstable during cold starts and at idle. Getting frequent system errors across different control units which reappear even after clearing them. I will schedule a full alternator diagnostic as suggested to prevent further electrical issues from these power surges. Any recommendations on whether I should keep driving while waiting for the repair slot?

Your situation sounds exactly like what I experienced. Given those voltage readings and symptoms, I strongly advise minimal driving until the repair. My circuit protection systems were already showing strain from similar power surges before I got it fixed. The fluctuating voltage readings between 12.8V and 15.2V are a clear sign of voltage regulator failure, identical to my case. The flickering headlights at idle were one of my first warning signs too before things got worse. I made the mistake of continuing regular driving for about 2 weeks after noticing these electrical issues. This ended up damaging my battery beyond repair and affecting several electronic control modules. The high voltage spikes from the faulty regulator put excessive stress on all electrical components. If you absolutely must drive, try to: Keep trips short and essential only, Avoid heavy electrical loads (climate control, heated seats), Monitor voltage readings, Park where you can get assistance if needed, Keep jumper cables handy The repair will likely be similar to what I needed, replacing both the voltage regulator and alternator. The total repair cost should be around 300 Euro depending on parts availability. The investment is worth it to protect the rest of your electrical system from permanent damage.

Thanks for the detailed feedback and warning about continued driving. Those voltage readings indeed look concerning, especially the 15.2V peaks during power surges. Your experience with the failing voltage regulator matches my symptoms perfectly. I just called the workshop and managed to get an emergency slot for tomorrow morning. Not worth risking more electrical issues and potential damage to other components. The car electronics are already showing signs of stress from the voltage fluctuations. The service advisor confirmed they will do a complete alternator diagnostic and check the circuit protection systems. They quoted around 350 Euro for parts and labor if both the voltage regulator and alternator need replacement. Seems reasonable considering the potential damage from letting the electrical issues continue. For now I parked the car and will have it towed to avoid any problems. Really appreciate the quick replies and shared experience, helped me understand the urgency of addressing these power surges before they cause more extensive alternator failure. Will update once the repair is completed.