battery light is on. mechanic says battery and alternator are fine.

Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. So sorry to hear you're having trouble with your TL. The battery light usually indicates a charging issue, which is not related to the starter. If your alternator and battery are good, it might be worth checking the connections between the alternator, battery, and ground. Corroded or loose connections can cause intermittent issues like the one you're describing. It's also possible the voltage regulator inside the alternator could be malfunctioning, even if the alternator itself seems okay. The starter shouldn't trigger the battery light, so getting a second opinion might be wise. If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!