Steve, thanks for the advice there. I don't have a meter handy, unfortunately (one of those round-to-it items I haven't gotten around to

), and this of course is a time where it'd be handy. I'm trying to remember where the ground connection for the battery cable is located. Was it somewhere in the passenger side fender?
I'll make a note of the items you've listed, and I'll likely be bringing the car back to him on Tuesday to have him attempt this. Thanks again.
Anyone got anything else I can have checked out?
EDIT: Forgot to mention, I checked into something else last night. I opened the door so the interior lights would be on, no key in the ignition, and pressed on the brake a few times to see what would happen. No flickering of those lights, though I also noted that unlike some cars, the brake lights didn't light without the car on. So I put the key in and turned it to ON (didn't start it), and stepped on the brake a few more times. Just about every time I got a little dim from the lights. They pretty much stayed steady unless I was doing that. Turned on the headlights and did it again, got some momentary dimming from them as well on brake pedal presses. So it does kind of sound like what you were saying, Steve. If anyone else has an idea of what might be afoot, lemme know. Thanks again.