Um. As it happens, in my day job, I contend with corrosion on connectors from time to time. Not, I emphasize, with Tesla-like connectors, so everything I'm saying here is from a slightly-better-than-a-tyro person.
First off: If those pictures, above, are your connectors, they've seen better days. But what I'm seeing in there is all the crud built up at the base of the connector pins. So, it's crossing my mind that it's not corrosion on the pins themselves (that would, presumably, lead to high enough resistance to prevent decent contact) but, rather,
partial shorts between pins because, often, crud is conductive.
That would kind of fit with your, "If it's dry, it's fixed".. because water saturated crud is, of course, a relatively decent conductor of electricity. And, to my knowledge, the Tesla's computers are
designed to pick up excessive leakage.
Tesla probably took one look at that and invoked the Nuclear Option: Swap out the connector for one that's clean. And, just because we're funning around here, I note that the bottom right thin pin has some Green Stuff around the base. My understanding is that those two thin pins carry the communications protocol between the car and whatever charger/wall-connector/wall-connector one might have. An open there would also do the business.
Another oddity is that there's little rubber gaskets at the bottoms of three bottom pins.. and they look slightly mangled and off-center. Um. That can't be good, either. One sec while I take a look at the ones in my 2018 car M3..
Ha. No gaskets and very, very clean.
Finally: connectors have
wires on the other side that are connected to the pins in some way. I have no idea how Tesla does that. If you have corrosion on one side, you
could have corrosion on the other, life being life. (As a random guess, that's one reason why gaskets: To keep stuff from leaking through.)
So: From your pictures, it looks like the design of that power connector was different in 2018 from when you got your car. Second: There's no crud down there on mine, but there sure is on yours.
So, first things first. You can wait for Tesla to replace the connector. I have zero doubts that that'll fix your problems, probably permanently.
Second: If you're feeling adventurous, you might do something about cleaning out the crud. Before adding any grease, please.
First, with the following, there's a risk: There are electronic cleaners of various stripes. And there are plastics, some of which don't take kindly to certain kinds of cleaners: i.e., they'll melt.
Having said that, the most common electronic cleaner found in most households is denatured alcohol. I use it at work pretty frequently on circuit boards; the kind of circuit board I'm familiar with is built out of FR4, which is fiberglass impregnated with resins. A little denatured alcohol after a soldering job cleans out the left-over rosin flux without trouble. And the kinds of components used on the boards upon which I work have never had an issue with alcohol. But, with all things, One Never Knows.
So, if you're willing to take a bit of a risk, get a Q-tip and some denatured alcohol. Go to a piece of the black plastic that has a
long distance to anything else and, with the Q-tip, put a thin smear on the plastic. Stand back: Look for bubbling, softening, or anything else, and don't use much alcohol. Let it dry, and inspect: Did the plastic get damaged in any way? If it did, forget it and wait for Tesla.
If you get past this part, being very careful, repeat the test, but this time, put a
tiny bit of alcohol on one of those gaskety things at the bottom of the connector area. Again, look for anything untoward. If it the rubber gets softened, mushy, or anything like that, cease and desist and go to wait-for-Tesla mode. (Remember that I said there were risks?)
If nothing tries to dissolve on you, get busy. Using that swab, and other swabs, clean the heck out of the bottom of the connector. Get rid of as much crud as you can, using multiple Q-tips to get in there and do the deed. Hopefully, after you finish, it'll look more like mine (smooth, black plastic) down there.
Note that none of this will make your gaskets straighten up and fly right. But, if you're
very lucky, you'll stop having water humidity issues after the cleansing.
Still think you'll want that connector replaced, although, being out of warranty, you'll have to pay some $$ to do it.
)
