I bought a 1997 4 Runner fog light harness kit on ebay for 25 bucks and it works for the Scion Tc. Basicly the kit comes with the relay, fuse, the complete wiring harness for the fog lights, and rocker switch that fits the Tc. The rocker switch is like the xB switch not the button type that the Tc uses. I know you can buy a relay for 5 bucks and make all the wiring yourself, but this kit comes with the wires already protected in plastic casing. The kit is made by Hella for the 4 Runner. This kit's power switch works independantly of the Tcs lights. But if you ground the switch to the right wire that powers on when the parking lights are on, you can have all the features of the Tc auto off system. The only modifications I had to do was to extend the grounding cable and extend the left light wiring by one foot.

Planning on installing IS300 fogs soon. Hope this helps out those that don't want to completely make a harness themselves.

 

Thanks for the info

 

That Toyota 4 Runner harness I bought on ebay was a pain the ___. What was suppose to be easy turned out to be a small nightmare. After I did the install and wired everything up to the right places I plug in the relay and nothing happens. I scratch my head thinking what the heck was wrong. I test every circuit/wire to make sure that all did not have a broken ciruit. Nothing was wrong with the wiring. I even tested the lights bulbs to make sure they were not duds. After ruling out everything else, I was left with the impossible.......the harness was wired to the relay incorrectly from the factory. They had the + wire from the battery running to 85 on the relay. The Ground was on 30 on the relay and the switch was on 86! It was suppose to be + from battery to 30, switch wire on 85, and Ground to 86 and power to the lamps/aux on 87. The part was made in Mexico for Toyota by Hella. I dunno, but some color blind worker was working that day. Made me waste two hours trying to figure out what the heck was wrong with it. Then, they run a ground and a switch wire to for the rocker switch. I assumed wrongly that the non light typed rocker switch needed a ground and switch wire only. You only use the ground wire if you have a switch that is lighted. You need to find a wire that turns on and tap into it and wire that with your switch. Just make sure you check factory wiring before you go crazy figuring things out if you go this route.

 

Thanks for the update. You have pics of install?

 

can you draw up a wiring diagram on which wire you switched on the relay? I am also planning on installing the is300 fogs.. and that 4runner harness looks to be the easiest.

 

Hopefully, if you get the same 4 Runner harness the wires won't be in the wrong slots in the female plug. There are only four wires in that female adapter which holds all fours wires for the relay. The relay is a standard relay that you could get at any automotive store. It's a 30 amp 12v relay and has only four prongs. The prongs are labeled 87 on top, 86 to the left, 85 to the right, and 30 on the bottom. Like I said before, 87 is the power to the lights (green in the kit), 86 is the ground (black), 85 is the wire that runs to the switch (yellow), and 30 is line from the battery's positive terminal that has to be fused with a 15 amp fuse. The kit has all this set up for you hopefully but mine kit in particular was wired incorrectly from the factory. Just check the wiring before plug in your relay. I powered the switch from a wire that was green with silver marks from the original fog light harness in the dash. Search under a post by Limey, he tested and found that wire turned on when parking lights powers on, so thats the wire you want to tap into to connect to the other end of the switch. Everything works fine now. When you cut with that drummel, do it very slowly when you cut near the corners of the fog lights, be very conservative with each cut so you gauge how much to take off to make a nice fit. Don't cut the bottom much because you need to save that to mount your IS300 fogs. The top, you cut off but don't cut too close to the edge, save like 2 inches at least, you want to leave a flap on top and a big flap on the bottom so that they will hold in place easily. I mounted them with small sheet metal screws 1/2 in length straight under the fog lights through the plastic bumper, 4 screws in each light should hold it. I piloted drilled each one. To keep the light steady in place I used a sheetmetal bracket that I mounted to the side of the metal frame bumper and screwed it into the bottom of the lights after adjusting the level. I didn't drill into the car frame, just took off the sensors and used the two holes from that for the sheetmetal bracket. That sensor, I am taking about is right next to the fog light mounting position, I think it's an airbag sensor, I am not sure. Just disconnect your battery before you mess with that. You dont want your air baqs going off cuz you took it off. I just didn't want the light to change position when the cars is moving. Another thing that I did that was a little different than how some people have inverted the lights is that instead of fliping the entire light unit inside the housing, I decided I wanted to the fine adjustment feature of the original fogs, so I cut the metal light casing down the middle with my drummel and rotated the cut off without effecting the mounting points of the light. I glued the halves back together with Nail Power from Lowe's. I am sure you can use any strong epoxy to glue to the metal halves back together. I used the cutting disk and small cylinder sander to cut the corners. Good luck.

 

Don't use Nail Power, that stuff melts under heat, I am gonna drill small holes and attach the two halves together with small metal strips. That should hold up to the extreme heat of the light bulb.