Headlight switch harness
 

So I've been having an issue with my headlight switch; it keeps frying. The person who had the car before me spliced the fog lights into the running light wiring, so they both turn on from the main switch, so I'm assuming that this is the reason I've been burning switches. I also noticed that this last time, the harness side connector for the switch burned. Can I use the harness from the s4 fc on my s5? I haven't been able to find any wiring diagrams. And could there be another reason I'm burning up switches? I'm down to my last junkyard switch and am hoping to avoid having to buy a new one...thanks.

You can't run lights through the headlight switch and expect the extra current to NOT burn the switch up.
That is your problem.
Take the fog lights Off the circuit and put the Headlight switch back to stock.(or uses a relay to activate the fogs)
or Use a relay and switch for the Fogs.Separately.
and get the proper switch and harness.S4 uses s4 ..

Awesome, thanks. I've already cut the fog light wiring out of the circuit. I was just wondering about the switch harness, because there's a parts car kind of close, but its an s4...Guess I'll hold out for an s5.