Booyah

I did this to my 4-Runner that was pretty simple but,
is there a way to do a quick mod that allows the Fog-Lights to stay ON when you go to High-beam? Basically you will also be able to cut just the fogs on with only the parking lights on as well.

NexVision

There's gotta be a control wire/switch that can be cut or bypassed which sends the signal to cut the fogs when the brights are kicked on if you have a wiring harness diagram shouldn't be to hard.

Capirato

Perhaps you can connect the wire going to the Fogs to the Tail-Light wire.

~ Cap

gsobol

Anybody has a wiring diagram? We could figure it out from that, and hopefully be able to mod the relays and not cut any wires.

mwbuck

Heres the first wiring diagram:

va204707.pdf

mwbuck

and the second:

va204708.pdf

Good luck!

Booyah

Ok someone figure this out

gsobol

So far it looks like you have to get to the back of the combination switch on your steering column. If you pull RedWhite cable from position 17 and connect it to position 16 (WhiteBlack cable), that should work. I need to verify it though. It looks like the combination switch interrupts grounding for fog lights relay, when the position of the high beam switch is in flash or high position. Since the fog light switch is part of that combination switch, there is no other way to get around it.

Booyah

Thanks for checking this out! If you can confirm this and make this happpen on your GX that would be great......

gsobol

Anyone has the pages from the tech manual that show how to get to the combination switch?

Lou19

I agree. Is it possible the Ground is interrupted by the timing delay? Where are the #16 & #17 connections? Any pics?

Thanks,
Lou
OIF Vet

gsobol

OK, I looked at it again and - NO, the ground is not interrupted. The Body ECU is responsible for turning the Head Relay on and off. When you flip a switch to turn your headlights on it actually sends a signal to ECU to turn the relay on. When you flash your high beams it does the same. One thing to note is that when you flash your high beams, your low beams flash too! Well, that makes sense since there's only one relay responsible for delivering power to all the lights as well as the fog lights relay, so when your lights are off the fogs won't come on period, even if combination switch gets rewired. Also, if I rewire the combination switch the way I outlined above, this will cause the fog light to flash along with the high beams and low beams as long as the fog switch is flipped on.

Another interesting thing is that the high beams are grounded directly through the combination switch. Which is weird since there would be like 10A going through it (2x60W@12V), just weird. So if anyone decides to put high power bulbs, just be careful. Unless of course I'm reading the layout wrong.

OffsetZ33

Anyone figure out how to do this yet?

gsobol

If you want minimum modification, you have to get to the combination switch in the steering column. Unplug the plug from the combination switch and pull the red/white cable from position 17. Connect it to the white/black in position 16. Red/white cable is much thinner, white black is much thicker. That's it.

There are three screws securing the plastic steering column cover, two are in the front (turn the steering wheel 90 degrees left and right to see/access them) and one is on the bottom. When you try to pull the cable out of the combination switch plug you have to lift the flat cover on the top of the plug (that's there to secure the prongs from accidentally falling out of the plug) and you have to use a tiny screwdriver to lift the latch holding the prong inside the plug and push the prong out of the plug.(access it from the connector side, not cable side) I hope I'm explaining this clearly, if you ever taken any plugs apart, automotive, computer, or others, you now what I mean.

I can confirm this is a working mod. This also allows you to turn the fogs on and off with the existing fogs switch. This mod will also cause your fogs to flash along with the highs and lows when you flash your high beams when the lights are in the off position.

Now, as I outlined above, it looks like all the lights power is controlled via the headlight relay. I guess this was done to let the body ecu control the lights??? I don't know, but it's not possible in current setup to run the fog lights without the headlights, unless you run your own wiring. You would have to locate the junction connector 7 & 8 and look for a red/yellow wire in location E J8. This supplies the (+) power to the fogs relay once the headlight relay is on. You would have to connect this wire to another source of power i.e. position lights.