Thanks for the suggestions. The only problem there is that a) the battery tested fine, and b) the alarm went off after I disconnected the ground on the battery.

It could be that the battery on the alarm is very, very small and discharged with the 8 or 9 alarms it issued, but I doubt it: the sound never warbled or decreased in volume. And when I yanked that ground cable, it silenced immediately. I'm not doubting the separate power supply claim; only that I could open the doors, etc with the battery removed and there was no alarm.

I'll search the forum for how to reset/reprogram the keys on the FOB, though I must admit I'm hesitant to do so. Worried if I get it working again, the alarm will engage and then get stuck again....

Mark