[Walt Fricke]

You need access to a wiring diagram, which will answer all this. Pelican has (at least had) a copy of a factory wiring diagram on its site. Any diagram from '74-89 would do, and probably even an earlier one. Maybe someone has posted a copy of the relevant page. A search ought to get you to what you need.

Porsche did not use relays for the headlamps.

You should be able to figure out what relays are what, and what fuses are what, if you still have the black plastic cover for the fuse box. They are molded in to the inside of the cover. Still useful to have reference to the wiring diagram.