Is the breaker faulty? Would a new headlight switch correct this problem? I only ask because I'm assuming it didn't do this when it was new.
Matt
Could be the switch is getting old/worn out or it could be your wiring is older has more resistance then when it was new and more resistance=more amp draw. I didn't read through your thread so if you have a new wiring harness that probably isn't it. Are those stock headlights or the aftermarket upgrades? The upgrades draw more amps and the relay kit is almost mandatory to stop the flickering.