300D elect windows quit?

[Fredmburgess]

Ran a search but didn't find a silver bullet, yet. Electric windows in my '84 300D have all worked until yesterday, at which point the both left windows and rear right quit (up, fortunately) while the front passenger works just fine...

Before I go digging, do these three or all four windows have anything electrical in common, like maybe a single relay somewhere? 1 or all would make sense. 3 out of 4 is weird!