The lights should be controlled by a relay. By flipping the switch to your headlights you power the relays coil allow power to be applied to your fog lights when you flip the light switch.

You just need to power the relay's coils with your parking light power wire instead of your head light power wire.

Don't have a gen III wiring diagram handy but that would be the next place I'd look to find your fog lamp relays. Then figure out which lead is hot when your parking lamps are lit and tap from those lights. <img src="/forums/images/graemlins/kewl.gif" alt="" />