Suggest you get a multimeter for measuring voltage, check continuity, etc. Very useful for electrical issues and checking.
Amazing deals on this 7 Function Digital Multimeter at Harbor Freight. Quality tools & low prices.
www.harborfreight.com
There are links in that post for the update process, clearing adaptations, etc. I do this for forum members for free. I will PM you my contact info in case you have questions.
I tracked down a multimeter and started testing. At the battery terminals under the hood I was getting ~ 12.3 V and at the battery I was getting 12.4. I would then try to start the car and it would not crank and after a minute no power at all. I retested the terminals under the hood but now I was only getting ~ 5V, and at the battery still over 12V.
I took a break to give some thought as to what might be going on and then tested the battery again. As soon as the positive probe hit the battery post there was a click like a fuse had been reset. (Both places testing at 12V again). Tried to start and same thing, like a fuse blew.
Long story short the positive battery terminal was a little loose and was causing the issues.
I then followed your instructions to clear the adaptations, cleared the errors and was able to take a short drive.
I think it was truly dumb luck that this power issue didn’t occur during the ECU update.
I will dig into whether the updates (ECU etc) were successful over the weekend or early next week.
I just wanted to make sure to thank you for the guidance as I was getting pretty close to having the car towed to a repair shop (which I really cannot afford right now).
Very much appreciated.