Sometimes it is just a bad battery
“Never attribute to malice that which can be adequately explained by stupidity.”I bought an old BMW some time back. I took it in to the dealership for an inspection before purchase and I mentioned that the A/C wasn’t working before inspection. They charged me what you’d expect (plus extra to diagnose _just_ the A/C) but gave the car a completely clean bill of health aside from the A/C, which they attributed to a bad blower motor.I asked the seller to have that fixed before sale, and they took it to another shop who replaced the blower…and still nothing. That shop kept the car for 2 more weeks and came up with nothing for answers. They took it to another BMW dealership who inspected it for another week and came up with nothing.So I turned to Google. Found a likely problem, but needed BMW dealership to confirm with proprietary tools. The BMW dealership had no idea what I was talking about. I had to literally tell them “can you plug in the foo widget and go to the bar screen and check the baz value shown there? Now can you hit Reset in the corner?” Magically, the A/C started working.I’m not sure how “right to repair” plays into my story. My real point is that technicians are human and imperfect; troubleshooting is hard. It’s not necessarily a conspiracy that they make mistakes, nor is it personal that they believe the diagnostic data in front of them over some random person _convinced_ it’s a specific problem—even when it seems completely obvious once the problem is fixed.