Can an ECU problem "fry" the alternator?

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Your mechanic’s claim about the ECU (engine control unit) frying alternators isn’t common, but it’s not completely out of the question either. The ECU does control how the alternator charges the battery by regulating voltage. If there’s a fault in the ECU or wiring harness, it could potentially send the wrong signal and overcharge the alternator, causing it to fail. However, three fried alternators in a row raises an eyebrow—I'd check for bad wiring or grounding issues before pointing at the ECU. A faulty voltage regulator (which is often inside the alternator) could also cause repeated failures. Or get a second opinion. Go to repairpal.com and find trusted shop in your area! If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554.