Thanks for the input.

Last night I crawled under the dash and had a look at the CEM. There are several fuses on the aft face, but I didn't see any relays.

The problem is quircky. I drove the car for about 30 minutes late afternoon yesterday with NO failure. Then later when I cranked it up in the garage it DID fail on the RH side. When it fails it doesn't slowly go dim or do any flickering - it just shuts off. If I turn the key off and then restart the engine, the headlight will burn again for about 3-5 seconds and then shuts off. (Turn the key off, restart the engine, headlight comes on for 3-5 seconds, shuts off, etc., repeats scenario.)

I did notice one thing though - If I just turn the key on and don't crank the engine up, the light will burn continually without failing until I turn the key the rest of the way and start the engine, then the light fails in a few seconds. When I just turned the ignition on without starting the engine, I didn't leave it on for more that about 20 seconds, so maybe if I would have left it on longer the light would have eventually failed. But I'm old school and feel wierd about leaving the ignition on without the engine running.

So what does this all mean? Possibly the higher voltage created by the running alternator is triggering the failure where just running the lights on battery power doesn't???? I'm just reaching for reasons at this point. If I don't come up with something brilliant over the weekend I think I'll take the car to a local independent shop that has the Volvo VIDA system and have them run a scan and see if they can identify something. With our older cars I've generally been able to buzz out problems like this myself, so it's a blow to my shadetree mechanic ego (and my wallet) to have to take it to someone else to troubleshoot it. I don't know if I'm going to enjoy owning a car that's smarter than me.