Optra Overvoltage and Electrical Issues

Sounds familiar. I had similar gremlins in my Chevy Optra, although I don't recall the exact model year. Start with checking the battery's health, but also, have you had the alternator tested? Overvoltage can often point to issues there. Any recent work done that might have messed with the circuit protection?

Yeah, I was leaning towards the alternator too. Had the battery checked, and it's showing as heavily discharged, but the overvoltage is still present after charging it. What exactly was your issue, and did you get any specific fault codes?

Mine was indeed the alternator. The voltage regulator was shot, causing the overvoltage and subsequent system failures. I’d strongly suggest getting the alternator tested, or just bite the bullet and replace it. It's a common enough failure. Afterwards I would recommend visiting your workshop to clear the error memory and check the functionality.

Thanks for the heads up! Turned out you were spot on. Workshop diagnosed it as a defective battery causing a domino effect of errors, plus a faulty alternator regulator. New battery, regulator replaced, total cost 290€. Problem solved!