Dirk - Sorry I didn't see this thread until now. What a great educational thread. Glad you got it sorted out without sending it to the stealer.
My 2020 is still fairly clean under the hood. I'm going to take a picture of that connection on my car and see how it compares. I personally would replace that terminal and probably that nut ... if there's enough slack in that wire to do so without splicing more in (not a fan of splicing in extra length). And also, there's some goo you can add to that joint that greatly slows down the corrosion and should keep it at least where it's at and not get any worse. I forget what it's called, but will look it up if you're interested. I'm sure I have some and you can just have it, it's just a small tube as I remember. Something like Nolox.
And, if you have any more problems with your A/C, we can do a meetup and I can evacuate it, hold a vacuum and recharge it to the exact spec. Not expensive. The refrigerant is whatever it costs. My labor will only be $999.
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View my fuel log 2020 Mirage ES 1.2 manual: 42.4 mpg (US) ... 18.0 km/L ... 5.5 L/100 km ... 51.0 mpg (Imp)