Goat7

We have a new to us GMC G20 1989.
On the way home the tail lights shorted out, after many hours of searching I found the culprit.
From the headlight switch(now brand new) there are two brown wires, one running to the front and one to the back. The one to the back shorted out causing it to melt all the way from the back to the switch (enter lameness here) Melting the orange wire to it. I tracked the orange wire and was able to replace it. I have ran a new wire to the back supplying power. But I still need to figure out where the one brown wire is suppose to supply.
I now have brake lights, reverse lights, signal lights but no running lights.
The brake light and signal light both illuminate in the red tinted section on the cover and the reverse light in the white section.
I don't know where the running lights should be?
Is there a relay I need to check?
should there be front running lights as well?
The side markers are flashing with the signal, is this correct or should that be running lights?

Thanks so much for some help, I would rather stop pulling my hair out

SWHouston

Side markers should not flash.
Cut the brown wire on the far side of the melt (away from power source) then jump a hot lead from the battery to it, to see what it lights up.
Front marker/Parking lights should be on, on both switch positions.

Goat7

Great. thanks for the help.
Should the marker lights come on when the headlight switch is off, or just on?

SWHouston

Off means everything.
So ON in either position (first notch park, or second notch run/drive)