Originally Posted by kpr10is

I just did lilsid112's fog light install. He directed me to see if I could help out...my thoughts were the same as above, it would have taken me much longer to figure out all the OEM wiring than to just run my own aftermarket relays, especially being that I install audio/electronics for a living. My brain couldn't wrap itself around that OEM harness, but I had the switch and my aftermarket relays figured out in 2 minutes, especially since I was putting HID's in at the same time, so the headlight plugs in the OEM harness would have to go to ballasts instead of the bulbs.

So, I decided first to figure out the switch, and run everything else on my own. The first thing was that Red and Red/black at the switch are not needed. The factory wiring diagrams I have access to say that these go to the interior lights system...whether that means they light up a bulb in the cluster that tells you your fogs or on, or what they do I'm not sure, but the less complicated this install the better.

The blue wire at the switch is the 12volt input to it. So, if you want your fogs to have the ability to come on whenever the key is on, hook this up to an ignition source. If you want them to only be able to come on when the parking lights are turned on, hook blue up to the positive parking lights wire (this is what I did). The switch is still primary, so this doesn't mean the fogs will come on automatically when the key is turned (or parking lights engaged) unless you leave the switch in the engaged position.

The black wire coming out of the switch goes to ground. That only leaves the green coming out of the switch, which is +12v out when you push the actual switch to engage it. Doing this will also light up the little green light on the switch itself.

I ran that green wire to trigger external relays, which sent battery power to the HID ballasts. The bumper was already pulled off, so I mounted the two relays behind it. If you are unfamiliar with relays, heres what I did:

Green wire from the switch went to the #85 spot of BOTH relays.
86: Ground
87: +Battery input
30: +12v output; obviously the 30 from one relay powering one of the lights and the 30 from the other relay powering the other.
If your relays have an 87a terminal, it isn't used.

If you aren't doing HID's and are following what I did, you can still use part of the factory harness that comes in the kit. The two pin plugs with (1)blue/yellow and (1)black wire are good...if I wasn't doing HID's I would have probably used this harness to run over to my relays behind the bumper, and cut this harness to the length I needed at this spot where my relays were. The two blue/yellow wires would go to the two #30 outputs of the relays, and the black wires to ground. But in my case, doing HID's at the same time and having ballast wiring on top of it all (I always run battery power to HID installs because they sometimes pop headlight fuses) it was easier to just run my own wiring and call it a day.

Keep in mind that working at a stereo shop, I had plenty of extra relays, spare wire, connectors, ring terminals, etc on hand. Each relay got a 16 gauge wire going straight to the battery with a fuse in line, a ground wire, a 16 gauge out from each relay to its corresponding light (or ballast), in addition to the wire i ran from the switch's output to the relays. I also used a bunch of wire loom which we had on hand, and of course, the two relays. So, if you are doing this install this way, that gives you a general idea of what you'll need.

Hope that helps someone out.
-Kevin