[RumblingREX]

DIY – Independent Fog Lights



This mod is based on the 05 STi. I have 02 WRX schematics and the wire color coding didn’t match up. I am ASSuming that the 04 STi color coding is the same as the 05. For the WRX, a different source of accessory power will need to be found(radio?) along with color coding of the wires.

The other posts I have seen that modify the stock fog light system are adequate, but not how I wanted them to function. This is not for the electrically handicapped. If you have patience, can comprehend the written language, and have the basic tools/skills, you can do this mod. All standard disclaimers apply. The described set-up works perfectly on my car. Do this at your own risk!

Function: This mod will allow the fog lights to be operated as long as the key is at least in the accessory position. They will turn on/off with the toggle of the fog light switch.

Tools:
- Wire cutters
- Needle nose pliers
- 10mm socket and ratchet wrench
- Red, black and green wire -22 AWG or larger
- Electrical tape
- Wire strippers(wire cutters if you don’t have the proper tools)
- Flat head screwdriver
- (4) Red butt crimp connectors


- This is quick and dirty. I apologize. I will add a schematic when I have the time to electronically draw one.

- Disconnect the negative terminal on your battery.
- Dismantle your dash under the steering column….. should have no problems getting to the fuse box.
- Remove your fuse box(1 nut and 2 tabs), and release your relay block from the metal hanger(needle nose pliers are key). Reattach the fuse box. You will not be making any connections to it.
- Locate the relay 4th down from the top. Turn over the relay block and on that 4th relay, locate the black/wire and blue/white wires. Cut them leaving about a 2 inch tail. (You can cut them shorter, but it will be a beotch to reconnect them back to stock later if you so desire.)
- Cut two lengths of 22AWG or larger wire to about 2 feet. I used a green wire to connect to the black/white wire and a red wire to connect to the blue/white wire using the crimp connectors.




- Next find the connector for the fog light switch. On the back of the connector, cut the black/white and blue/white wire leaving about a 2 inch tail. Connect the green wire from the relay to the black/white tail on the connector using the crimp connector. Cut a 1 foot black wire, 22 AWG or larger. Connect the black wire to the blue/white tail on the connector using the crimp connectors.
- Cut the yellow/green wire and tape both ends.
- Connect the black wire to ground. I used one of the nuts for the fuse block.
- Connect the red wire from the relay to the yellow/red wire on the intercooler sprayer switch.
- Test and reassemble everything. You are done.




Hope this helps! A much cleaner Mod! Cutting the black/white and blue/white wiring, you effectively take out the Subaru fog light controls and wire in your own.

I plan to use mine as driving lights. I can't read the radio and clock when the lights are on during the day time with sunglasses on!

[Datadatum]

While the fog button light doesn't work unless the headlights are on, this modification was pretty simple:

Simple foglight mod

Edit: Link updated from old forum location

[RumblingREX]

I started with that thread when I took my dash apart. But my main goal was to have them on as driving lights. I didn't like having the dash lights dim during the day and didn't want my parking lights on.

[Datadatum]

Actually, that earlier thread results in complete independent operation of the fogs. You just don't get the nifty little fog button light to come on unless the headlights are on. It can be hard to tell if the fog button is in or not.

I drive frequently with my fogs on, and no other exterior lights (in the daytime ).

[LESLIEx317537]

Wait, so your fog green indicator lights up when the fogs go on now too?
Nice.
I was gonna mod that next, but I got lazy.

When I get a chance, I'm going to see if I can get the green light to go on too.

Im the guy who did the mod for the fog lights above in the link, and the auto intercooler spray.

<---Look my avatar with the fog mod I took last summer.

[LESLIEx317537]

My mod is much easier and can be reverted back to stock, while yours cuts the whole wiring harness. I also can do mine is 5 minutes, while yours takes like 30 minutes.

My fogs go on independently also with the key. I wired it to the stereo harness accesory on.

My question is, does your buttons green indicator light up when you have the fogs on and your headlights off?

My next mod for the fog light will be to get the green light on the button to light up. I figured out how to get the JDM intercooler switch to light up so I hope I can figure out this too.

[RumblingREX]

Sorry for the delayed response. I don't troll this board as much as I should.

To answer your question, yes the indicator light does turn on with the fog lights and with the headlights off.

On a side note, I wired mine independently because I didn't want to use the other circuitry involved with the stock set-up. You are getting your ground through that circuitry and hooking up a power source the way you did is risky. You could potentially fry the grounding circuitry with the unregulated +12V you are using. I tried every combo I could think of using the stock wiring, and none of them gave me the results desired. So I went this route. And even if you sell the car, I couldn't think of a reason to put it back to stock. Exhaust mod, yes; fog light button, who cares. No one will ever know as long as it works.

[cruzSTI]

What's the exhaust mod?

[kennyvb]

LESLIEx317537,
How did you wire yours?

[Datadatum]

Try the link in post #2...

[RumblingREX]

Originally Posted by cruzSTI

What's the exhaust mod?

I was just trying to reference any modification. I meant any exhaust mod, you don't want to sell you car with those parts on.

[LESLIEx317537]

How would I fry the ground circuitry using the stereos ignition-on wire?

You do know it is fused for the stereo. I mean if it wasn't all STi and WRX stereos would fry out.

I have a Full PC in my car (AKA CARPUTER) and I have no voltage problems. I have wired everything in my car and yet have to fry something. But if I do, I'll let you know.

I don't have a exhaust yet. Stock.

[speedsnice]

Are there any pics of this mod?

[Stargazer]

Originally Posted by speedsnice

Are there any pics of this mod?

Check out this link:

How-To mod the 2004/2005 fog lights to turn on with 12 volts

I followed those steps on my 06 STI and it works perfectly--no wire cutting. I used a piggy back fuse to get power.

[speedsnice]

Thanks for the link, I am gonna install my JDM fogs tomorrow so I will modify the relay before I install it.