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

canucklehead

The running lights are the same bulb as the brake. The bulb has 2 filaments. On the front it is the same as the turn signals.....
The daytime running light circuit could be involved if the van has that. There is a module that controls it and it comes on as soon as you release the parking brake...

Goat7

Great I am going to go explore some more. thanks