Looks like my left headlight failed properly. This morning it was working fine in the first 2 mile drive. It was raining and when I went to the second drive it flashed (like a strobe) and then failed. On/off did nothing to bring it back. The strobing makes me think this time it might actually be the ballast, reminds me of how an HID lights up when I don't have a bench power supply that is powerful enough to ignite.
Also have a couple broken tab headlights, with extra HID and ballasts so might try swapping out one part at a time to see what really failed