DIY: 2007 LGT Rear Fog Light in OEM Lamp Housing

[Gator GT]

Hi everyone, this is a DIY walkthrough for wiring into the existing brake lamp to create a rear fog light in the OEM lamp housing.

 

I used 12ga wire & I purchased a set of diodes from Radio Shack (#276-1144; comes 2 in a set) and spliced those in towards the taillamp.

 

People can decide which taillamp they want to tap into, but I've seen a pattern from European cars that utilize a single rear fog lamp (vs some Audi models that use 2 symmetrical lamps), and the lamp is closer to the center of the road/behind the driver. So, yes, the LH taillamp.

 

Before I get into the nitty-gritty, insert usual legal disclosure mumbo jumbo releasing me from any blame game should you develop any sort of electrical gremlin. Each car has the POTENTIAL of being different from the factory by means of a quality control oversight and your wiring may be different than mine.

 

PROCEED AT YOUR OWN RISK. kthanx.

 

CAUTION: DOT Regulation (according to member outahere) prohibits the rear fog from being within 4" of the brake lamp, let alone same location. PROCEED AT YOUR OWN RISK.

 

Picture sequence:

1. Take kick and lower dash panels off.

 

2. Unclip the Relay Block.

 

3. Strip a small section of wire from the wire coming from the Fuse Box on the Fog Relay. You may be able to use the wire going out to the fogs themselves, but I wanted to tap the line PRIOR to it going through the relay. Note: Don't tap the trigger/coil wires.

 

4. Wrap Rear Fog Lead (RFL) around bare wire, solder and wrap joint in electrical tape.

 

5. Label RFL every 18-24" for future identification (optional).

 

6. Install RFL along wire conduit line leading to rear of car, which is located at sill, under trim panels and rug. Use of zip ties helps keep items tidy.

 

7. Trace RFL along existing wiring back to taillamp assembly.

 

8. See #7.

 

9. It is easier if you can take the pin out of the connector for the "BRAKE" function (BRIGHT) of the taillamp (vs. the pin for the "PARKING" function (DIM) of the taillamp). Snip a 1.5-2" length of wire out of the OEM "BRAKE" line to splice in the diode and not have extra wire length needing coiling to stay tidy.

 

*REMEMBER*: If you are heat shrink tubing, put that on prior to soldering the diodes in and send them up the wire towards the front of the car so the soldering process doesn't "pre-shrink" them.

 

I used 2 diodes, 1 on the "BRAKE" wire and 1 on the RFL wire, so neither lead will backfeed the other. May be overkill, but I didn't want any electrical gremlin surprises.

 

After splicing both diodes in, I spliced the RFL into the "BRAKE" wire DOWN-LINE and closer to the connector (in other words, the RFL wire is spliced in at a separate location all its own away from the diodes). Wrap in electrical tape.

 

10. Re-insert the pin into the connector at it's OEM location. (See below pictures for final description)

 

 

1.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Lowerdashremoved.jpg

 

2.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Fogrelay_thumbon.jpg

 

3.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Fogrelaypoweroutwirestripped.jpg

 

4.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Rearfogpowerleadpresolderfusebox.jpg

 

5.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Rearfogpowerleadlabelfusebox.jpg

 

6.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Rearfogpowerleadintrunk01.jpg

 

7.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Rearfogpowerleadintrunk02.jpg

 

8.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/Rearfogpowerleadattaillight.jpg

 

9.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/LHtaillightwiringwdiodes.jpg

 

10.

http://img.photobucket.com/albums/v628/g8rauctioner/Subaru/LHtaillightwiringwdiodespluggedin.jpg

 

 

 

So, when all is said and done, if you've properly identified wiring specific to your year and model car, your lights should function as follows:

 

A. When you turn your fogs on, your LH brake lamp will be illuminated at it's brightest stage. When you step on the brake pedal, that lamp will NOT change, it will stay bright. When you release the brake pedal, and your fogs are still on, the LH brake lamp is the only lamp that will remain bright.

 

B. When your fogs are off, your LH brake lamp will operate at the same level as your RH lamp. With fogs still off, and you step on the brake pedal, your LH brake lamp will operate as designed from the factory. If you should decide, while at the stop, you turn your fogs on, upon releasing your brake pedal, your LH brake lamp will REMAIN at it's brightest stage, while the rest of your brake lights dim/turn off.

 

At any point in time, if wiring was done correctly and in respect to your individual year and model car, you can perform the following sequence in any order and not harm your car (so long as your parked in a safe location!): turn fogs on, press brake pedal, turn fogs off, release brake pedal.

 

 

If I've missed anything or lost you, let me know.

 

have fun!

[outahere]

Nice write up, but most drivers in the USA are unaccustomed to a separate rear red fog (even a factory installed one), and having a rear fog lamp in the identical location to the rear brake lamp will be even more confusing to following drivers, and increase their reaction time to your brake lights coming on. Plus it is illegal to have the rear fog lamp and brake lamp occupy the same position (DOT regulations). There is a minimum distance requirement between the rear fog and the brake lamp (4" IIRC)

[Gator GT]

realllllly......hmmm. pissa. That, I was not aware of.

 

Well, it's done, and I'm not undoing it unless I get knocked for it.

 

You know, it's funny...I've seen some Volvo and MB have the rear fog right next to (in the same housing) the brake lamp. Audi and SAAB are the only ones I've seen (OEM) that have separate locations.

 

Come to think of it, I think BMW is in the same pool with Volvo and MB, iirc.

 

Thanks, none the less, outahere for your input.