3rd Brake Light Wiring Info

This is to help people find the wiring for the 3rd brake light. The red brake light on the roof above the rear window. I'm installing a brake light flasher into my 3rd brake light only. I didn't want the flasher to affect the tail lights. I could not find any info on the wiring, so I removed the headliner to trace the wires.

There are 2 main wires that runs from the fuse box in the front of the truck to the 3rd brake light. Once the wiring harness reaches the 3rd brake light housing the wires branches off to each bulb housing. I tested the wires with a multimeter to confirm which one was 12v power and which one was ground.

Solid Dark Blue Wire - 12v Power (Shows 12v when brake pedal is pressed).
Pink with Black Stripe Wire - Ground.


I double checked the wires at the rear driver door floor panel and confirmed that these are the only to wires in these colors that run along this path.



The path of the harness runs on the driver side, down the rear pillar, through the floor panels, towards the front of the truck. *(I initially assume it ran through the headliner with the overhead lighting wiring harness. That's why I removed the headliner. I'm glad I did though as it gave me access to the back of the 3rd brake light).


So now I can install the brake light flasher behind the rear driver seat or around the fuse box under the steering wheel. If you are looking for a brake light flasher as well, they are mainly marketed for motorcycles. They have different flash sequences you can pick from.

 

Thanks for the pics and the write-up. Can you explain the brake light flashers to me? I am unfamiliar with what that is

 

I'm sure he'll correct me if I'm wrong...I hope anyway...feel free TMS.

But I think it just flashes (whatever you want. In this case just the third brake light) a couple or 3 times really quickly when you hit the brakes. It's supposed to draw attention from someone behind you, and I guess it does. More-so at night than during the day, I'm sure.

 

As another driver the flashy 3rd brake lights really grind my gears. But they no doubt work, seeing as I notice them more (and get more annoyed)

 

I would double check that pink wire with a black stripe if I were you.

The ground wire should be white wire with a black stripe.

 

I put a flasher module inline (blue & white/blk wires) in my 15. It flashes 5 times fast, 5 times slow, then solid on. You have to use leds instead of the regular bulbs that are in there.

 

This post is just what I was looking for to install the Stop-Alert flasher module I bought for my 21 DCSB Tacoma. So where is the best/easiest place to splice into the wiring for my 3rd brake light with this module in your opinion? I don't wanna have to take down my headliner if I can avoid it; and I also want a location where the module itself can be tucked away. So I don't know if it'll fit under the driver's side door sill or somewhere else. Please advise. Thanx much

 

It is tricky to install these, but here's how to do it right without removing the headliner, or risking a leak whenever it rains: Find the positive wire, and all the other wires, and put them in a garbage can. Make sure the module also goes in the garbage can. Now you won't irritate the rest of the world with this obnoxious and useless contraption, plus your brake light won't leak and your roof liner won't rattle.

 

I would take a min and read the laws on these light modifications….
They are illegal.
Just a heads up..

 

They're actually legal where I live. Which is all the more infuriating. They can blink 3 times in unison. But in rush hour traffic that means they will blink 3 thousand times per mile. And even if they blinked 3 million times, that still doesn't change whether or not you will get rear ended. It's a crapshoot.

Heres what I do, in the 0.001% of times when it's actually appropriate to signal other drivers of a sudden stop: I press the brake pedal multiple times to get their attention, maybe throw on the hazards. Of course I can only do this after stopping, but this has two benefits... in that 0.001% case, my brake lights aren't randomly blinking off in the middle of a panic stop. I don't want someone looking up from their cellphone to see any of my brake lights off, when I'm in the middle of a panic stop. Secondly, in the other 99.999% of cases when I press my brake pedal, I'm not irritating the shit out of everyone behind me, with an obnoxious and useless brake light flasher.

You can check the math, this works out to 100% of the time. That leaves 0% of the time for when you should ever install a brake light flasher, for any reason, ever.

 

I’m surprised (seriously) that a local vehicle law overrides a fed law.
I would be interested to see how that would pan out outside cal.
Not bustin on ya, just making an inquiry.
Have at it and stay in Cal.. lol

 

Fed trumps state law 100 times out of 100. There are exceptions where the federal laws are there only to be in effect where the state otherwise has no law and therefore doesn’t override other state laws, but these are clearly spelled out in the laws. This gets interesting with pot, as still completely illegal under fed statutes. This is an enforcement issue and not thefact that the state laws are overriding the feds. This also is pretty common. Every once in a while the feds remember that our union is a collection of states and those states have certain rights to uniquely govern their constituents.