Ok, based on several good suggestions, both here, and on the rat.net, here's what I've done and found out:
I pulled the alarm connector plug on the alarm connector, and measured across the #3 and #5 prongs, and measured 0 resistance. Then I tried to measure voltage across the alarm connector itself (cover plug removed) and didn't get any voltage with the key on, and the starter button pushed. I measured resistance across the starter button, and got infinite resistance, whether or not the button was depressed. When my room-mate comes home, I'll ask him to help me verify that.
I ran a jumper wire from the positive terminal of the battery and connected to the B (spade) connection that wasn't grounded, and the engine cranked over, even with the key turned off. I'm guessing that means the solenoid is good??
I positively identified the starter relay (staring right at me), and with the key turned on, measured battery-equivalent voltage across 4 of the 5 connections (on the harness side of the connection, relay removed), the one exception being the black/pink wire. I measured across the relay male connections and got infinite resistance across all but two of the connections, the blue and blue/yellow ports, which is the way it should be, according to the main circuit diagram. I'm guessing that the relay is good???
So right now, looks like the starter, starter solenoid, and battery are fine, along with the starter relay and alarm connector. Does that sound right?
Thanks again for all of the support!
