I put too much trust in my battery and hit the road this morning only to have it die on me.
The Expedition is now at the shop.
Based on what I saw and heard yesterday when I was making my feeble attempts to check the alternator with my voltmeter, and based on its gutsy, powerful start this morning, I thought the battery (with no headlights on) would get me 10 miles to the school and back, and then I could connect it to the charger.
I never got a chance to figure out whether the voltage regulator alone could be blamed! It's got 95,000 miles on it, so maybe I should have just gone for the whole alternator...
Too late now. Sure the shop will get money for labor, but that's okay. They're good guys. It's just that my Expy is my hobby truck. I'm supposed to keep it running while the shop fixes all my newer vehicles. So really the biggest bummer about all of this is my lost opportunity to gain knowledge and experience.