79 C10 brake light (and headlight) question

[Jonboy]

I am chasing a problem with my brake lights, and need help. I have power at the switch on the pedal, but none at the lights. Where does the wiring go from the brake light switch? Does it feed back through the fuse box? The switch is working, as one side is hot until the switch is opened, then both sides are hot. I tried to check for power at the harness behind the fusebox, but nothing there.

On a semi related note, my headlights have been wired to work only when the key is on. Where does the headlamp switch pick up power? I know it is one of the large red wires. Does it come from the junction box under the hood?