5th Gen Independent fog light mod.

This thread is a result of some interest I had from my question about my fogs that did not work properly after the dealer installed them.

http://legacygt.com/forums/showthread.php/fog-light-question-223689.html

 

This is an easy mod but you need a moderate wiring ability and some basic tools for automotive wiring. You will need a few feet of wire, a wire tap, some crimp on connectors, a few zip ties and the basic hand tools to do simple wiring.

 

1- Tap into the yellow wire at the back of the parking light...I used the one on the left side because it a shorter wire run.

http://i.imgur.com/1SznDhY.jpg

 

2- Remove the OEM fog light relay....note where the various contacts are located on the relay and in the fuse box.

http://i.imgur.com/eVnFC8a.jpg

 

3- Make 3 short "Jumper" wires with appropriate fittings....this was my first one....later made shorter wires.

 

http://i.imgur.com/zZujZYt.jpg

 

 

4- Connect wires as shown into the proper fuse box spots....connect the wire that is tapped into the parking light to the remaining relay connector and ground the relay to the fuse box mounting bolt.

 

http://i.imgur.com/Qm6WInq.jpg

Replace the fuse box cover and zip tie the wire from the parking light to keep it tidy and out of the way.

 

 

The fog lights will now work in high and low beam but not with your DRL's if the steering column stalk switch is turned to the off position.

 

DRL's with no fogs

http://i.imgur.com/zne0Nx3.jpg

 

Low beams and fogs

 

http://i.imgur.com/0QUR3p7.jpg

High beams and fogs

http://i.imgur.com/TnHNsyb.jpg

 

You should be aware, before you do this mod, that you cannot turn your fog lights off with your high or low beam head lights on.......If that is important then cut the wire from the parking lights (Yellow in my pics) and run it into the interior and connect it to a separate switch which will break that circuit and give you direct control over the fogs being on or off at any time.

I did this switch mod with a simple toggle switch in the dash right by the OEM fog switch........... works great

 

Cheers

I can't wait to try this!! I have been wanting to have just my fogs on with out my headlights... and to stay on with high beams.

It will be interesting to see what nstg8r thinks of this.

I can't wait to try this!! I have been wanting to have just my fogs on with out my headlights... and to stay on with high beams.

 

This mod does NOT allow fogs without headlights...but it does allow fogs with DRLs

 

BTW since I posted this I also cleaned up the wiring a bit with shorter jumper wires and cleaner wiring ..... looks better under the hood but works the same.

This mod does NOT allow fogs without headlights...there is another little "work around" for that but I have not done it yet...maybe in the neat future??

 

BTW since I posted this I also cleaned up the wiring a bit with shorter jumper wires and cleaner wiring ..... looks better under the hood but works the same.

 

Fogs without headlights involves re-wiring the switches to bypass the BIU or just using new switches. The BIU is what controls all the relays.

It will be interesting to see what nstg8r thinks of this.

 

I'm out of town right now and my laptop doesn't have any of my "vacation" pics on it. Once I get home Saturday, I can inspect the wiring diagrams to comment further.

looks awesome but def want to see the mod that allows the fogs on by themselves

^^yep, that's what I am interested in too. A truly "independent" fog light.

For those who want a truly independent fog light control there is a very easy way to do it.... no relay involved.

 

http://i23.photobucket.com/albums/b375/RM-RS/2_zpse8396b8d.jpg

 

Remove the stock relay and make a jumper wire between the relay spots marked "Power" and "Lights"...that turns your fog lights on even when the car is NOT running. Run that wire into the interior to an independent switch with the appropriate fuse inline and you can turn your fogs on or off anytime you want.

I don't like to run lights without relays but that will give you truly independent fog light control.

I did it as a test to make sure it works.... It DOES!!

All you need is about 8 feet of wire, some crimp on end connectors, an inline fuse holder and a switch (Toggle, push button etc)

 

Again I will say that you need some basic wiring abilities and the proper tools...... "Back in the day" we used to wire lights like this all the time...power to the lights ... a ground source and a switch with a fuse.

It looks like if you disconnect the line from the BIU to the fog light relay (the violet wire with a yellow stripe - goes to pin 4 on the relay) and run a splice from the white wire going to the fog light switch in its place, you can turn on the foglights independently. (it looks like all of the logic is in the BIU - so it must check to make sure the low beams are turned on and the highbeams are turned off)

BIU??? Built In Unit?

Body Integrated Unit. If you blow it a new one costs about $2000.

For those who want a truly independent fog light control there is a very easy way to do it.... no relay involved.

 

http://i23.photobucket.com/albums/b375/RM-RS/2_zpse8396b8d.jpg

 

Remove the stock relay and make a jumper wire between the relay spots marked "Power" and "Lights"...that turns your fog lights on even when the car is NOT running. Run that wire into the interior to an independent switch with the appropriate fuse inline and you can turn your fogs on or off anytime you want.

I don't like to run lights without relays but that will give you truly independent fog light control.

I did it as a test to make sure it works.... It DOES!!

All you need is about 8 feet of wire, some crimp on end connectors, an inline fuse holder and a switch (Toggle, push button etc)

 

Again I will say that you need some basic wiring abilities and the proper tools...... "Back in the day" we used to wire lights like this all the time...power to the lights ... a ground source and a switch with a fuse.

 

The method I would use would be similar to your other mod using the relay.

 

Instead of running wires from the "POWER" & "LIGHTS" to a switch in the cabin, run them to the relay as you did previously. Then, you tap +12v switched power from the cabin fuse box, run that to a SPST toggle switch, run a wire from the switch back to one of the coil poles of the relay, and then finally the other coil pole of the relay to ground.

Yes...exactly the way I would do it...I posted this "Simple" solution to show it can be done....I always run relays for extra wiring for lights.

 

This would be the cheap and dirty way for those who want it fast and easy.

Yes...exactly the way I would do it...I posted this "Simple" solution to show it can be done....I always run relays for extra wiring for lights.

 

This would be the cheap and dirty way for those who want it fast and easy.

 

The "simple" solution would be alright for aftermarket LED lighting, but for bulbs drawing 110W (55W each), running that wiring direct to a toggle switch in the dash is a bit of a fire hazard.

Precisely.....

As I have said...I would not do it that way BUT is shows it can be done and it is up to the person doing the mod to ensure that it is wired safely.

I think you could also just bypass the BIU and use the foglight switch to provide ground to the foglight relay - this way you would even have the little light on the dash work (but only when the headlights are on) - you could grab the lead for the switch at the steering column, then run it through to the engine compartment and grab the lead from the BIU under the main fuse box.

I think you could also just bypass the BIU and use the foglight switch to provide ground to the foglight relay - this way you would even have the little light on the dash work (but only when the headlights are on) - you could grab the lead for the switch at the steering column, then run it through to the engine compartment and grab the lead from the BIU under the main fuse box.

 

Cut both A15 and B26 and splice them together.

Cut both A15 and B26 and splice them together.

but then the little light on the instrument cluster wouldn't work when the headlights are on

but then the little light on the instrument cluster wouldn't work when the headlights are on

 

But then you'd be sending 12 volts back at B26 from the relay risking bricking your BIU.

Fair enough - I was going with the assumption that they system was using 12V so it would see 12V either way. that would be something to check! (actually, since connectors B280 and B281 are right next to one another, probably the easiest thing to do is pull the respective pins from each connector and splice them together - keeps the BIU out of the equation and would be readily reversed) - I couldn't find the BIU in a parts list to see the cost - I figured it's cheaper than the ecm, but maybe not?

Of course, you could just add a few more relays to the setup to achieve the same effect.

Given that you two are obviously the wiring gurus on this site...I am surprised that neither of you have posted a walk through on this mod...be much appreciated by many, I'm sure.

I've already done mine, but I am sure there are numerous folks on here who would like a safe and doable plan.

Given that you two are obviously the wiring gurus on this site...I am surprised that neither of you have posted a walk through on this mod...be much appreciated by many, I'm sure.

I've already done mine, but I am sure there are numerous folks on here who would like a safe and doable plan.

 

Best way would be to draw a diagram, which I suck at.

Or actually do the mod and take pictures??