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Discussion Starter · #1 ·
Ok Folks...
I bit the bullet and tried the Tacoma Fog Light mod on my '07 Tundra.
http://www.tundrasolutions.com/forums/tacoma/57319-how-to-fog-light-modification/
The mod is supposed to let you run the Fog Lights anytime.. With or without headlights and with high beams on. Instead of the way it is: Only when low beam headlights are turned on.

I have a co-worker that has an '05 Taco and he has a friend that has an '07 Taco. Both work with the same mod, so I figured the Tundra would do the same.

I did option 3 in the above thread.. No worky..:mad:

The relay is set in the box where one of the silver pins is closer to the front of the truck and the other is closer to the rear. When you bend and hook up the front pin, the fog lights won't come on at all. No matter what. When you bend and hook up the rear pin, the fog lights will light with no other lights on, but they will turn off as soon as you turn on the parking lights or head lights and will only turn back on when all other lights are off (except DRL)

No mod ever mentioned bending the copper pins, so I didn't touch those.

When all was put back to original, everything works fine.

So, I have tried and failed using the simple Tacoma Mod. Who out there is smart enough to take my info, use it for what it's worth and come up with an '07 Tundra Fog Light Mod that works?:confused:

Hopefully someone, because, evidently, I can't.:D
 

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I know the wiring is different with DRL's vs non-DRL's. It was that way on the 06 and previous years, I'd assume its the same on the 2007.

You really should get a test light too. This will help when trying to figure out what wires do what. You do have to run a wire from the fuse box under the hood inside the truck too.

It's been so long since I've done mine that I can't recall exactly what wires, but that relay under the hood needs "switched" power to activate the foglights. From the factory, it receives "switched" power from turning your headlights on. It already receives 12v power (other side of relay)

Your job is basically give that relay another "switched" power source (Accessory wire somewhere under the dash) and do it that way.
 

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Discussion Starter · #4 ·
Bringing up an old thread...I'm looking at the wiring schematic for the fogs on the Tundra and it looks like a jumper between 3 and 5 (in place of the relay) will make the fog lights able to come on when the parking lights are on...does this sound right?
I'm not a electrical whiz, so please excuse my ignorance. How would this be accomplished? Would you run a wire jumper from Post 3 to Post 5 and keep the relay in place? Or, would you pull the relay out and run a fused hardwire jumper from the slots 3 and 5 would go into as well as the doing it for the slots 1 and 2 would go in also?
 

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Discussion Starter · #6 ·
HUH?? :D

I see what you are talking about on the diagram.. But, as I said, I know nothing about this stuff.. What is the ECU FFGO and Main Body ECU exactly? I see it's a big box on the diagram, but what is it? Is the squiggly line with the "FOG" below it constitute the Fog Light Switch? Would my idea of just fused bumpering the two slots where the posts from the relay would go work? If so, why and if not, why not? I'm learning here along with trying to figure it out.. On another thought, is the power from 1&2 only being used to make the relay open and shut for 3&5.. What would happen if I pulled the relay and just jumpered the slots for 3 and 5 and left 1 and 2 open? Thanks..
 

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Its the computer. It is creating the ground (0v) so that the fogs turn on with the tails but when you turn on your high beams it takes away the ground (by switching to 12v) and the fogs turn off. If you were to just ground that point, when you turned on your high beams you would be shorting the computer's output to ground - poof. Ford charges $1500 for a computer. I can only imagine what Toyota would charge :eek:
 

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Discussion Starter · #10 ·
Is anyone working on this...I'm getting anxious...
Me too.. But, after reading a lot of the threads on some mods, people like to make things so much harder than they need to be. What's wrong with a simple fix? A buddy of mine with a Taco just added LED's to his cup holders and it looks sweet.. He was reading on how other people did them and they made it sound so hard. Not sure if people think they sound smarter by making hard or not.. I just know it makes me not want to read the post and figure out my own way. He figured out his own way and they look great. They dim with the dash lights and, it was a SIMPLE mod.

There has to be a simple way to do this without frying the computer.. I just don't know enough about any of it to try any more than I did.. I'm wondering what's wrong with wiring the hot post on the DRL to the outgoing post to the fog lamps and leaving the computer out of it. The way my simple mind works when your DRL's are on, the fogs should work. I don't think you could turn them off that way, but they would run without your headlights being on. But, I'm sure there is something wrong with this simple plan too.:confused:
 

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Just for the record, I set about to do this today (just for the hell of it) when it occured to me that this mod will render the switch useless. Personally, I would rather have a functioning switch than fog lights that are on all the time (following the tails, of course).

If anyone is interested, here is how the circuit works:



Consider first the three fuses "FOG", "ALT" and "LH-J/B" each of these is connected directly to the battery and brings 12v to relay contacts for both "TAIL" and "FOG".

With the tail lights on, the ECU (computer) outputs a logic low on its "TRLY" line. This 0v provides a return path for current to flow through the solenoid (coil) of the relay causing it to engage and brings 12v to pin 1 of the "FOG" relay.

When you turn on your fog lights, the ECU now outputs a logic low (0v) on its FFGO line engaging that relay and allowing current to flow through it to the fog lights.

Whew

Anyhow, if we break the connection from FFGO and ground it (on the relay side), indeed the fog lights will remain on when the high beams are on ('cause there is no computer to tell them to shut off) but we lose control through the switch because all it does is tell the computer: "Hey, I would like the fog lights on".

Anyone still interested in doing this mod should either:
find the J4 connecter to the ECU and nip off the wire to pin4 and ground it (fuse panel side)
or
find AJ10 and nip off and ground the wire to pin 8 (fuse panel side)






So there is the info. I'm not doing it as I'd rather have a functioning switch so someone else will have to run with this (and photodoument!)

I've got another mod I'm doing today and will post it this afternoon.
 

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You could isolate FFGO from the ECU as PS-RAGE had said, and then use the fog light switch to switch pin 2 of the fog light relay to ground. This may mean cutting two wires off of the back of your fog light switch and soldering to them.

Then the fogs will follow the tail lights, and the fog light switch will be functional.
 

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Same here. I did it on my Rubicon, by adding a relay, but it was a hit & miss deal.
 
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