I've shared the information about 1) what the problems and symptoms were, followed by 2) the expert shop's diagnosis, 3) the resulting repair, and finally 4) the 100% success of this repair in restoring full functionality to the car. It's strange that someone would now be still telling me to "focus on the main battery" or some such, since the problems no longer exist and the main battery was always fine and was never the source of the problems. This is what bias leads us to, fixation on irrelevant things.

 

What was the repair? Any explanation?
.
.
.