Rear fog light - EDM/JDM spec, factory look
 

Added an OEM looking, rear fog light. Looking at proper usage online via articles and videos it does increase visibility in foggy/heavy rainfall conditions. I believe this is standard in the JDM/EDM market and I'm surprised why it's not standard on North American vehicles. I believe red is the usual colour for a rear fog light but I settled on amber (VLED). I tried red and found that it blends with the tail lights and just looks like one tail light is out. I chose amber because it differentiates from tail lights and had a higher lumen output than red, also from VLED.

I have the Diode Dynamics Tail as Turn mod which can provide reverse lights in 2 locations, the factory turn signal location and the factory reverse lamp location. I didn't want 2 reverse lights on each side and for a few months have left the factory reverse location without a bulb, as I think it's a cleaner look. After seeing a post on Trail4Runner.com about rear chase lights I was inspired to do something similar. Here are a few shots. No, I don't plan on having them on all the time, strictly for low visibility conditions.

Factory look switch - but actually waiting for a REAR fog light switch so this one is temporary.

Red is the standard color for all other countries. It's supposed to be the same intensity and color as the brake lights when they are activated

Rear fog light should always come on with front fog lights. Why would there be a need to control them independently?

Amber/Yellow are indicator lights, not fog lights, and should be used as such. People are just going to assume one blinker is broken and stuck on.

I played around with a red bulb as well. It seems to blend in with the tail lights too much. Others may just think I have a brake light out or a tail light out. So I settled for amber. At the very least it differentiates from the tail light and brake lights.

I also played around with the idea of having them on with my front fogs. But sometimes I just feel like having my front fogs on for no real reason. Just for the look sometimes. Don't want the rear fog to be on as well when not necessary. Plus I don't like splicing into factory harness to achieve that result. This is only for visibility in foggy, low visibility conditions and use as a chase/dust light when off pavement.

Demon is 100% correct.

My Audi had OEM rear fogs that did not have to be on when the fog lights were on, but couldn't be turned on without fogs.
Even with red lights, you will be seen. People may think that your brake lights are stuck on, but at least they will see you, that's kind of the point.

This thread has what I did with red brake light bulb in the trailer hitch

https://www.toyota-4runner.org/5th-g...Rear+fog+light

I will play around again with the red bulb but will keep it amber for now. The real test is during foggy conditions but who knows when that will come.

Yup have gone through any thread I could find regarding rear fog lights and the one you linked I have gone through a few times. It's part of where I got the idea from. This one from Trail4R also gave me ideas but didn't want to cut a hole in my bumper.

Baja Designs S2 Chase Lights on 4Runner Roof Rack or Bumper

Just adding a side by side if anyone was curious.

Just adding a video for the question, "but why rear fog light?"

YouTube

I should add that rear fog lights are a great safety feature. Well done to pursue this concept. It's something that is easily overlooked, but makes a significant difference in being seen by others - especially at highway speeds.

The red is much more noticeable. I would go with that.

I have the tail as turn module as well; what did you modify to get independent control of the reverse lights vs. the turn signals as the module comes?

Well I actually came across a free cracked tail light assembly luckily from a local 5th gen FB group. I removed and cut off the reverse light socket from the harness. There are 2 wires that are attached to it. (If curious, the part number for the tail light harness is 81555-35400.) Instead of using existing reverse light socket, I removed it (still attached to harness, pushed it aside) and used the extra socket in it's spot. Then I simply ran two wires to the front. It is powered by an empty slot in the fuse box, with a fuse tap/add a circuit inline and the button wired in as well. The LED's are from VLED, I purchased an amber and a red 921 because I wanted to test both to see what I liked better.

If you don't want to look for an extra socket, you can probably achieve the same results by tapping into the Tail As Turn harness or existing harness that feeds the tail lights, most likely the tail light wire - though I am not 100% so you will need to double check and test for yourself. And if you tapped that wire, it can only be turned on when tail lights/head lights are on. Mine turn on when the key is in ACC position, not just when the headlights are on.