Driving it with the scanner running, it’s showing 14.0-14.2 V while driving around 50 mph. When I stopped at a stop sign, foot on the brake, it dropped to 13.2V.

The thing that makes my gut keep coming back to the alternator is the battery died a couple times a few months ago. I took it in to the auto parts place to get it tested. They took it in the back, told me it was being tested and would take a couple of minutes. I took it there because the battery was a Bosch with a date showing it was 10 months old. 10 month old batteries don’t normally go dead. They can but it’s unusual. After 40 minutes they said it wouldn’t complete the test and they honoredthe Bosch warranty and handed me a new battery for free.

That seemed to resolve the dead battery problem.

Maybe I’m wrong and I’m trying to project the problem onto the alternator but the fact that a few miles earlier, it was showing Engine Failsafe with the DSC Disable message and Brake light come on makes me think it’s electronic not mechanical.

I guess I’ll pick up the 510 scanner. Can I read the ECU with that or is the 520 needed for that?