I do not get why I can't upload photos, really annoying.....
You can run a temp wire to power what you think is the headlight wire. You can tell for sure at the connector behind the headlight. When you look at the removed plug the left wire is high beam, the top one is low beam, the right one is low beam. Well should be at least. Yes, shops build cars, rarely are most of them good at electrical. As Cycleguy said it's a free for all. I have an original harness, unused I'll take a look at it and try to determine what color coding etc they originally used. One way to narrow it down is that the "parking/dash" lights are common to both switch positions. A test light (i call them idiot light), and a multi-meter are going to your best friend in this case. I would also gain access to your headlight, clip on a temp ground wire to the frame or handy bolt, try your switch, see if it lights.
https://www.amazon.com/Painless-8015...86811995&psc=1