yuch.
this is my C500 connector; taken apart I am guessing for the first time. An 85 vintage; with the original manufacturer's elect grease still actually keeping the terminals from corroding but also unavoidable acting as a dirt trap. This is about as 'sealed' a connector as you will find anywhere and THIS is how much crap got into it.
SO..
something to think about. Then think about every other connector in the entire car and how much LESS protection they have from corrosion and dirt entry........
and don't be surprised by elect gremlins.....
(one side male; one side female. Between them there's GOTTA be a problem....!)
And the car doesn't have to be 19-20 yrs old, either. I had a 92 Astro van that (at the ripe old age of about 5!) started having repeated probs with the blower switch. I replaced about 3 of them before I noticed that one (only ONE!) of the mini spade connectors had slid back inside the plastic connector and so wasn't making proper contact anymore. So it got hot. So it oxidized. So it got hotter yet. And melted the plastic a bit more. And made an even POORER connection. Etc etc etc. That is how it goes. Good lesson for me on how touchy electrical connections can be and how important.
So THIS mess?!?!?! cleancleanclean and then seal it up. (clean)....