You'll need a wiring diagram. On the off chance all the bulbs are blown or sockets are corroded, id pull those out and visually inspect the filament in the bulbs and look for blue corrosion in the socket the bulb goes into. If that checks out, then id be inspecting if the multifunction switch is sending signal to the fog lights and low beams to turn on. then id be looking at an inline connector that controls all 4. But I suspect the multifunction switch has failed