OK, another check through the service manuals reveals that power supply routing MB-10 is indeed switched, off the RH head light relay in fact. So we can't simply jumper that to +12V, because that would end up making one head light shine all the time. And we can't easily isolate the fog light system because the location of the "split" (below B62 on the diagram above) isn't indicated.

In any case, here's the illumination system diagram, merged for your viewing pleasure. Hmmm... wonder if anybody's solved this little conundrum yet?

 

Ok, searching over at scoobymods is making my head hurt -- too much noise and problems. But it seems like the only way to do it right is to jumper directly to the relay, bypassing the existing wiring completely. That means:

 

And here are the relevant scoobymod links:
http://www.scoobymods.com/forums/sho...ight=fog+light
http://www.scoobymods.com/forums/sho...ight=fog+light (PDF link no longer works though)

And here:
http://www.scoobymods.com/forums/sho...&threadid=1022

The key is the "have your cake and eat it too" section, but the wire colours seem to be different for the GC's and the GD's...

Sigh.

 

Ha... yea that diagram makes my head hurt too! I probably won't bother with just the "fogs only" part, let me know how it turns out if you do it. Pics if possible.

On another note, my dome light always pops on for about 20 seconds after shutting the car down. During the day I don't care but at night it gets annoying if I want it to stay dark in my car right when I kill the ignition. Any thoughts about this one? I haven't figured it out yet.