Retread,
There should be no connection between brake lights and taillights.....except a path to ground in the light fixture itself.
If your brake/tail setup uses separate lamps, the tail light might be finding ground through the brake light filament.
This is a new area for me, so I might be all wet. If you take a close look at the lamps when the problem is happening, you might see that the brake light is actually 'trying' to flash, but is only going slightly dim as the current from the tail light powers it.
You can clamp a wire to a clean spot on the frame and touch it to the base of the suspect lamp...this might cause thing to magically work.
Keep 'me' posted...I'm trying to learn 'Grounds-101'.
Stuart
