no single fuse would affect only both brake lights (and not affect other illumination areas). 2. I pulled the panels off the back and confirmed that all bulbs were OK from visual check. 3. I had my son press on the brake pedal as I removed the brake light sensor and I noticed that the brake lights would come on depending how I flexed the Brake Light Sensor. 4. I unplugged the sensor and a quick check of the PC board confirmed that a solder joint was cracked on one of the connectors pins...and 2 others were ready to fail. 5. I was lucky this time...finding that it was an intermittent problem when my Son was pressing the brake pedal down.