Thanks for all the ideas...
I shouldn't have been so quick to discard the idea that it might have been a fuse. That's exactly what it was!
In the fuse box closest to the front of the vehicle, there is a row of 3 red, 10 amp fuses. The fuse closest to the windshield was, indeed, blown.
Even better, there were two spares enclosed in a yellow plastic wrapping right in front of the problem fuse row.
Mechanics couldn't figure it out which led me to believe that it couldn't have been something simple. "A wiring issue", they said.
Gotta love it.
Thanks again, for the brainstorming!