I didn't get any comments or suggestions, but I proceeded to run the experiment anyway.
I had concluded, based on my bulb swapping, that on the brake circuit, one LED on one side and nothing on the other side caused the fastest flashing, without the ignition or lights even turned on. When another LED was added to the "empty" side, the added resistance reduced the speed of the flashing by about half. (remember this is a brake light, turn signals and all other bulbs are not turned on. The key isn't even on. When I replaced one of the LED brake light bulbs with an incandescent bulb (1057), the flashing stopped completely.
Therefore the speed of the brake light bulb flashing (right bulb only in every case) was related to the resistance in the brake light circuit. Low ohms equals fast, higher ohms equals not so fast and higher ohms yet equals no flash at all.
I added (1) 6 ohm, 50 watt load resistance in parallel with the one brake light LED bulb that flashed and all flashing stopped.
Further testing reveals that all the bulbs on all corners operate as intended under their correct operating conditions, determined by the light switch, turn signal switch, ignition key and brake pedal. Only one bulb is not currently working under any conditions - the right front parking bulb. It's the one that operates with the rear parking bulb when you need to park on the left side of a busy street at night. That bulb needs its socket or its ground wire connection cleaned.
I've never heard of this problem before, and based on the heavy interest the problem drew (none), no one else has either. Anyway, it's nice to have a solution, even if it's a "fake" problem. "Fake" things are popular these days. The right bulb uniqueness probably has to do with a slight difference in the drivers of the two bulbs. I don't have the time or interest to explore the anomaly.
On to other things.
Tom Kizer
Levis, Quebec, Canada