Fog Light Operation

[DLubecki]

My goal is to have the 4Runner fog lights operate the same as the Tacoma fog lights. The 4Runner’s only operate with the headlights, the Tacoma’s will operate with either the parking lights or the headlights. I printed out the wiring schematic of both vehicles. The wiring is virtually identical, with the exception of a wire splice on one of the vehicles and an actual contact terminal on the other, and one of them is grounded to a different ground terminal than the other. Besides those two things, the wiring is the same.

I looked up the part numbers for the turn signal/light control stalk. They are different part numbers. 84329-12150 & 84329-0R020. I think the first one is for the 4Runner, the other for the Tacoma, but we were going back and forth between pages, I could have gotten the order wrong. Either way, something about them is different. I think it could be the internal contacts that make the lights operate. My first question for anyone who would know, if I were to install a Tacoma stalk into my 4Runner, would that be enough to make the fog lights work with the parking lights. Also, since I don’t have both parts laying out in front of me, are the plugs the same, could they even be swapped out? Finally, how hard is it to swap the stalk? Does it involve removing the steering wheel, or is it more simple than that?

Sponsored

 

[127.0.0.1]

tacoma fogs behave exactly the same as 4runner. only available when
headlights on low beam. per FMVSS standard.
EDIT: nope, OP is right

if they behave differently they have been modified by owner.

older vehicles was a simple jumper in the relay box. current
models is canbus controlled and not a simple jumper.

if you want control of fogs get a britebox

tacoma harness

4runner harness

what did you use for wiring diagrams ?

 

[DLubecki]

I’ve played around with one at the dealership. They do in fact operate with just the parking lights. It also states that in the Tacoma owner’s manual. (Ford, GM, and Dodge also operate this way.) I think the Tundra is also the same, as I’ve seen one on the road with the parking lights and fog light on. That’s why I think the contacts in the switch are different.

 

[mfoga]

I going to agree it’s probably not a contact but a software thing. The switch is just telling the system the lights can be turned on when available.

 

[127.0.0.1]

well what do you know, I'm kinda shocked Tacoma does do this

 

[127.0.0.1]

I refreshed my knowledge on FMVSS. they regulate aim, output, and photometrics of fogs,
but not when they can be used. That is left to state regulations.

 

[NotApplicable]

Is there a functional reason to operate them without headlights, or is it an aesthetics thing?

 

[127.0.0.1]

I don't think it is as easy as a new stalk. all signals go to the body ECU and that makes the decision to illuminate or not, based on how the 4runner is programmed.
you can use aftermarket aux switching and wiring, or britebox which can do it, but britebox anytime will still need an added aux switch.

 

[mfoga]

Is there a functional reason to operate them without headlights, or is it an aesthetics thing?

I could see it useful in foggy situations where you would like to have only the fog lights on for less reflection off the moisture in the air.

 

[NotApplicable]

Some interesting tidbits

https://www.slashgear.com/1952442/is-it-illegal-to-drive-with-fog-lights-what-to-know/

 

[127.0.0.1]

I could see it useful in foggy situations where you would like to have only the fog lights on for less reflection off the moisture in the air.

yellow is awesome in dust. cuts right thru it. easier to spot rocks or chuckholes when following. white sorta sucks in dust

 

[Twisted]

If changing the turn signal stalk works I'd be interested. For now I have a BantamX controlling the fogs with the factory wire as an input. Works like stock but if I want them on for any reason without headlights, or to stay on with high beams, I just turn them on via the BantamX and leave the factory switch off.

For anyone doubting that the fogs come on with just parking lights on a Tacoma I can confirm they do. Had one for a loaner for a week.

 

[DLubecki]

Is there a functional reason to operate them without headlights, or is it an aesthetics thing?

I always used them during dawn and dusk, when headlights aren’t needed, but a little something is nice. I’d also use them just before or after rain, when the sun isn’t fully out. But there is a little aesthetics to it as well.

 

[DLubecki]

tacoma fogs behave exactly the same as 4runner. only available when
headlights on low beam. per FMVSS standard.
EDIT: nope, OP is right

if they behave differently they have been modified by owner.

older vehicles was a simple jumper in the relay box. current
models is canbus controlled and not a simple jumper.

if you want control of fogs get a britebox

tacoma harness

4runner harness

what did you use for wiring diagrams ?

I just saw the last question in your comment. I got the wiring diagrams from techinfo.toyota.com. The same place as your wire harness images.

Sponsored