[64Lemans]

Hello.
I've been working on fixing the wiring for the front end for some time now. I have finally gotten to the point where the parking lamps are working. Parking lights are on... directional works...the correct filaments are working when needed, etc... I replaced the headlight switch which solved most of my issues.
The passenger side marker light is lit...and works great. The only remaining issue I have is the driver side marker light. I know the socket and bulb are functional as ...when I was switching wires around, the light came on. But when I have the lamp / directional working the way it should, the marker light will not light up.
Looking at the wiring diagram, it looks like one wire is power and the other is going to the headlights. Is this a ground of some sort or ? Wondering if I could use the power from the parking lamp if needed. Any suggestions would be greatly appreciated. Thanks....