Both license plate lights are from Fuse 3. I neglected to check them when I had everything (fuse block, bulb check relay) apart. With Fuse 3 out, I removed the license plate bulbs and checked the resistance to ground of the lamp wires back to the bulb check relay and appears that they both are shorted to ground. I will still need to pull the lamp check relay to verify, as I suspected the relay was bad until I read your note.

It looks like finding the short and/or replacing the license plate wiring all the way back to the bulb check relay plug could be a real pain.