Help with no headlights. 1974 scamp. Blinkers come on instead...

crackedback said
There should only be power on the green wire if it's disconnected and either the red or violet if plugged in.

Showing power on all three at plug sure sounds like a missing ground or a series of them. That's smells of bleed back looking for a ground.

I found a short at a headlight connection once ( back of the left bulb ) that powered all at the same time. Dimmer switch seemed inop as the bulbs were higher beam regardless. They did work though. Has anyone considered blown out bulbs here?