For those of you that are looking to install factory (or i suppose aftermarket) foglights, you probably do not have the switch that comes with them when installed from the factory. You can simply buy this switch from Toyota, but it is built into the headlight switch and costs about 100 bucks.

The alternative is to simply wire in the required relay and your own switch. All other wiring is already there and ready to go.

1.) First you must install the foglights in the factory position. To do this, you have to remove the front bumper. This is easier than you'd think if you have never done it, there are the 4 bolts on the top in the engine bay, 5 screws underneath, 1 on each side and a couple of plastic push pins in the engine bay. Make sure to unplug the side marker lenses before pulling off the bumper.

2.) Next you should find a blue wire with a orange stripe with its harness on each side where the foglights plug into. For me, the driver's side was out in the open and easy to see, the passenger wire was taped back so it took a little looking to find it. (You may have to feel around blindly, but it is there!)

3.) The foglights have two bolts on the top of them and just bolt into place and plug into the wiring harnesses that are already there.

4.) Now you need to install the switch and relay. First you need to remove the driver's side kick panel plastic cover. There is a little plastic screw holding it in place, just undo that and the pull it out (you may need to remove the drivers door sill by just pulling it up, as they are connected). The picture below is once you have removed this piece.

5.) The harness circled in the picture is where the relay will be wired. The problem is that it doesn't just plug in (unless by some miracle you can find a relay that fits that harness). In order to wire it, pull this harness out, and from there you can pull out the four metal connectors from the harness (so essentially you will have 4 wires with connectors on them dangling. These will be plugged into the relay.

*I would recommend using heat shrink tubing to cover the outside of the metal connectors since they are no longer covered by their harness and could touch other stuff and short out or something.

So what are these wires??
The four wires you should find hooked up to that harness are a blue w/ orange stripe (sends power to the fogs), blue with red stripe (this is the power wire coming in to connect to the blue with orange), a red with white stripe (this is a power supply from the headlights, telling the relay they are on), and a green with black wire (this goes to the factory switch and will no be used, in fact it may not be present).

More about relays
The 30A automotive SPDT (Single Pole Double Throw) relay should have 5 leads. 30, 30A, 85, 86, and 87 (a good information source on relays is www.the12volt.com). 87A will be ignored, 30 is your input, 87 is your output, and 85 and 86 are your "coils" that act like a switch. When one side of the coil has a voltage and the other side has a ground, it will connect 30 to 87 (in to out).

Using the relay here
The blue with red is your input, so it goes in the input (terminal 30). The blue with orange is the output that will go to the fogs, so it goes in the output (terminal 87). The red goes to one side of the coil (either 85 or 86). This will tell the coil the headlights are on. The other side of the relay (whichever is left of 85 and 86) should be grounded. You will need to run your own wire here to a ground (there is a factory ground above this up under the dash and has tons of white wires connected to it. This is a good location to use). If you want to use a switch, put a simple switch here on this ground wire. If you leave off a switch the fog lights will come on anytime the headlights are on.