Thanks for the heads-up guys. I dug into the casquette a bit over lunch yesterday and tried to trace the wires for obvious connectivity issues. Didn't find any, but I'm sure it's just those bullet connectors not making perfect contact. Rode home lightless, but didn't get pulled over (or run over). When I get a free afternoon or evening I plan on rewiring that rat's nest to eliminate the connectors altogether.
In the meantime I'll try the jumper to see if the ground and hi/low beam leads are the problem, or if the bulb is blown.
I'd worried that it was an issue of throwing too much power at the bulb now since I'm not using incandescents for the little BA9s, etc. I read a post from the iron barrel forum that explains something about their headlights running on AC power, and that the AC regulator could be bad, etc. I figured these bulbs didn't care if it was AC or DC, but it's good to know that it's not a 'too much power' thing that burnt my bulb... well, that's assuming the bulb's not burnt out.
We'll see.
Thanks again!
Chuck