Regarding Fog lights. In my car the fog lights come on automatically when ever the car senses that either of the HID lights aren't functioning correctly.
I went ahead and measured the voltage on pin 3 on the head light plug. As I would expect I have 12v when the pathway lighting is active and the left xenon is on and 0v when the light switch is on and the left xenon is off. I have to assume that if under any circumstance I can make the xenon come on every time that the wiring is good. I mean that is what common sense tells me. But sometimes this car does defy common sense.