Topper 3rd Brake Light Wiring

UPDATE:

Finally figured out the plug-n-play solution that has no drilling & no tapping. Easy removal as well. Getting power & signal from the trailer connector using the following components:
Back of trailer connector ->
-> 1. USCAR 7 pin to 4 pin T harness
-> 2. CURT 58348 Trailer-Side 4-Pin Flat Wiring Harness
-> 3. 16 Gauge in-line 5 amp mini blade fuse
-> 4. IMPORTANT: AT-LC-8N LED 3rd Brake Light Logic Module
-> 3rd Brake Light

4 is crucial since some other logic module doesn't work well with LED lights. I used heat shrink tube at all connections and wrapped everything in 1/2 inch split wire loom tubing. It works flawlessly. Hope this is helpful for you guys
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Guys, is there a clean solution to wire the 3rd brake light on topper? I did some research and looks like there are 3 options:

1. Tap directly to the tail light -- I know there are quick disconnect connectors, but still don't want to mess up with the factory wiring if possible
2. 7-way to 4-way T harness -- Pro is it's plug n play, but seems the 4-way flat connector is for trailer light, so the 3rd brake light will blink when turns
3. FBC harness solution -- not available to the 3rd gen Tundra yet

Anyone has experience? TIA

 

Just tap into the brake
light super easy and clean use the quick connect T taps you can get them pretty cheap on Amazon. You won't have any issues if you do it right and it's hard to screw up. If you bought a canopy brand new that's how they would do it. I personally would avoid using my trailer wiring for it. If you have any thoughts of wiring a light inside your canopy you will need to run a line from the battery if you want it to work when the truck is off so you will need to bring it thru the bed behind the taillight anyway.

 

Brake and directional use the same lamp, so the truck interrupts the power when the directional is on. So if you grab power at the rear tail light, the brake light on the cap will blink when that directional is on.. If the cap is installed at the dealer, they will make it work.

 

Pretty sure even if it is the same lamp it is a different wire you tap into at least it was on the last couple I did. However I have not done a third gen but to me it makes sense that it has a different source it would have a different wire

 

On mine, at the tail light, there are only three wires. Running lights, brake/directional , and ground..

 

Here is your brake light wiring diagram.
Pin 5 lilac wire at your rear light connector.
Ground is pin 3




Turn signal is pin 2
Lavender/sky blue wire on the right
Beige wire on the left



Illumination, or parking light is pin 6 lavender/green wire
That wire color is a tough one to see..

 

That's odd, you don't even have a pin 5...
Although I don't know what a 'marker light' is, or the difference between a 'marker light' and a 'rear ID light'..

 

Mine is an SR5.....

 

Is that diagram for a gen 2 or gen 3? On the tacoma it has a 3 pin but I tapped the wires before the plug which had a brake only wire that spliced into the brake/turn signal pin

 

I have a canopy on order I guess I will be figuring it out soon enough

 

2022.

Ultimate TUNDRA Wiring Diagrams Collection | Toyota Tundra Forum (tundras.com)

Why would I post a Gen 2 diagram for a Gen 3?

 

Does the trim matter? Mine has the sequential turn signal, I know SR5 has different tail light. Maybe wiring is different?

 

So, I've run into the same problem mentioned in this thread in regards to my SR5 having only 3 wires/pins. Did anyone figure this out? I'm just trying to hook up my camper shell's thrid break light.

 

2023 SR5 and confirm only 3 pins in the taillight harness. My topper brake light operates just like the tail light its wired to. Meaning its on when braking and flashing when turn signal is engaged. I've been thinking about connecting it thru the trailer harness, but haven't dedicated the time to figure it out.

 

UPDATE:

Finally figured out the plug-n-play solution that has no drilling & no tapping. Easy removal as well. Getting power & signal from the trailer connector using the following components:
Back of trailer connector ->
-> 1. USCAR 7 pin to 4 pin T harness
-> 2. CURT 58348 Trailer-Side 4-Pin Flat Wiring Harness
-> 3. 16 Gauge in-line 5 amp mini blade fuse
-> 4. IMPORTANT: AT-LC-8N LED 3rd Brake Light Logic Module
-> 3rd Brake Light

4 is crucial since some other logic module doesn't work well with LED lights. I used heat shrink tube at all connections and wrapped everything in 1/2 inch split wire loom tubing. It works flawlessly. Hope this is helpful for you guys

 

GG offroad has a cable kit that plugs into the brake light harness on the rear of the cab and extends to the topper.

 

I was thinking about using his kit. But it needs access to cab 3rd brake light, also needs to run long wire from cab. Might worth it If you need to relocate the camera at the same time. Otherwise plugging to trailer connector is much easier.

 

The GG off-road and the one below are the two options I know of, which is basically what the OP did

https://www.ezwheeler.com/products/...ug-in-t-harness-300200?variant=44528711860468

I just let my canopy installer handle it. Dome light to the battery, lock/unlock to wires under the driver door sill, and brake light to a wire harness under the hood. That’s what their ‘book’ said to do, which they claim Leer develops with the vehicle manufacturers (who knows). It’s a splice which is a bummer but really not a big deal.

 

I'm guessing you don't have the digital rearview camera

 

Correct.

 

I did the same thing today, SR5 mine.
6 Running lights,
2 brake/directional ,
3 ground..
That is, connecting a third brake light from the taillight is not feasible, it will flash when turning.

I don't want to spend so much money on plugs to connect a brake light. I'm in Canada and these are over $200.

I want to tap the third brake light to the cab, but the disadvantage is that it requires a long wire. Now I have a question: How do I run the wire from the cab to the rear bed? Thanks If anyone could tell me. Or give a link..

 

You can put it through a grommet, I believe there’s one near the drivers seat.

 

https://www.ggoffroad.com/store/p/tundra-22-brake-cable

 

I pulled off the plastic panel on the back of the rear seat, driver side, and found a hole with a rubber plug.

 

Step by step.....

https://www.tundras.com/threads/truck-cap-3rd-brake-harness.147874/