Vintage Dirt Bike Q & A

I have a 1981 Yamaha XT500.After doing a major electric wiring overhaul I have a problem.Tail light flashes to the rhythm of the indicator.This is with the motor not running(can't be started currently).When I run earths directly to the battery from both tail light and indicators,there's no improvement.However if I run power lines from the tail light and/or indicator straight to battery it improves but doesn't cure the problem.Battery voltage is around 6.50 which is very good.Neutral tell tale on tacho dims to the rhythm as well.I've added and cleaned earths all over the place.Can anyone help me out.