Do the S5 cars have a dedicated fog light switch in the center console near the arm rest? Or do they tap into the running light / headlight switch on the dash?

I've only owned S4 cars so i have no idea how it is set up in the S5's

 

yes there is a switch in front of the arm rest. but they only come on after the head lights are turned fully on.

 

And only with the low beams.....

 

And the way they wired it up doesn't make it too obvious to change that....

 

I'll be running my own switch and relay so i can use them as driving lights / running lights whenever i please.

I was just wondering how the factory harness worked with them, mine never came with fogs from the factory.

 

there is a short little harness from the fog light to a connector on the main harness by the turn signals. after that it does some funky stuff, the fog light switch turns the fog light relay on and off, but the low beam relay powers the fog light relay.

the relays are up front, but the coolant overflow, it actually should have all the wiring in the harness

 

would there happen to be a write up about how to enable them to turn on with just the switch?

 

When i put mine in i'll write one up

 

i would be most appreciative!!!!!

 

This is just a guess but you could use a 5 pin relay with two 87 pinis. They have these in the auto parts store in the headlight and fog light section where I'm at.

Run a ground wire from the chassis to one end of the fog light switch, the other end from the switch to pin 86 on the relay.

Pin 85 would be go to a place that supply 12v when the key is turned to the on position

Pin 30 would connect to the battery (be sure to wire in a fuse, no idea what size maybe 30amp)

Pin 87 and 87 would connect to each fog light.

The ground wire on the fog lights will ground somewhere to the chassis

This way when you flip the fog light switch it kicks on the relay and provides power to the lights.

That should be it, just remember the 5 pin relay has two 87 pins, not 87 and 87A.

 

the concept is a little simpler than that, in the stock setup when the low beam relay is on, it sends power to the fog light relay. so to make the switch work all the time all you need is the fog light relay to be powered with the key.

HOW you would do that is the thing. the rest of the lights aren't switched power, they can be on with no key...

 

In that case instead of the switch 12v it would be wired directly to the battery (splice pin 85's wire into pin 30's wire). That was the only thing needed to complete the circuit is the ground via flipping the switch.