Background: I’m running a 2024 SD CC LB Limited with BLIS and smart hitch.

I am getting a trailer that has stop lights and turn lights on separate LED lights. But, the SD’s trailer plug (both 4-wire and 7-wire) have the stop and turn signals on the same wire. So, they need to be split.

They make both non-powered splitters and powered splitters that will split the brake wire from the turn signal wire. But, I’m getting conflicting information about whether I need a converter (to split the brake wire from the turn signal wire) at all and, if so, whether it needs to be non-powered or powered? I’m seeing a bunch of non-powered converters, but many of them say they won’t work with LED trailer lights. One pulls the brake circuit from the high brake light wire. Others suggest they need to be wired with diodes.

I assume someone has invented this wheel already. Could y’all please share your experience and insights because I’m going crazy trying to sort all this stuff out.

TIA

 

The trailer receptacle on the SD is a standard configuration that matches the standard trailer plug. Based on your description, the trailer plug on the trailer you are buying is non-standard. So, how does it mate with the truck? I would think the trailer manufacturer would have a solution, or recommended solution, for connecting to the tow vehicle. Is it possible the trailer already has the splitter electronics? That would make more sense. Otherwise, someone with different tow vehicles would need to modify the wiring on each one.

 

This.

Trailer manufacturers are required, albeit loosely, but required to adhere to the industry standard. Many moons ago, U-Haul got in trouble for this by having their trailers built with oddball wiring standards that would require an install of an adapter to tow their equipment. This led to many cases of vehicle wiring harness damage.

 

He never actually states that the trailer is new or was manufactured that way. Sounds to me like maybe a previous owner backyard engineered the setup.
Maybe some more background information from the OP is in order so that someone who has encountered a similar situation can help. Or perhaps in inquiry to the manufacturer if they did indeed send it from the factory like this.

 

I understand and agree about the trailer receptacle; it is a standard 7-pin receptacle we all use.

And, this apparently would not be an issue if the lights on the trailer were incandescent. Curt (#56196), DrawTite (#118158), and others have 2-to-3 splitters that work with non-LED trailer lights. Curt (#56424) will do the 2-to-3 split, but it's for 24V systems.

RecPro (#RP-1778) has a powered converter, but you have to pull a wire from the high brake light (like was done when my A.R.E. canopy was installed), but there is no way to get that wire into the 7-pin receptacle.

True Mod and Kody Technologies have powered 2-to-3 splitters, they both sell the same item, but they say it only works on Fords up to 2018. I don't know what changed with MY2019 to make that "signal relay" incompatible with the 2019-2026 Super Duties.

Does that clarify what I've gotten so far?

 

If I understand the instructions for the converters, they are intended to connect the tow vehicle to another vehicle being towed. The instructions say to connect the brake light output of the converter to the towed vehicles brake wire (I assume that means brake light wire). It is not clear what pin, in the 7-pin connector, is used for this purpose? Do you know?
Does the trailer have brakes?

 

The converters are commonly used when "dinghy towing" another vehicle. The trailer does not have brakes.

Yes, the brake output of the converter would connect to the brake light wire of the towed vehicle, but that would be a more complicated connection than I'm contemplating because the stop/turn lights on a towed vehicle are going to be combined, so you wouldn't need a converter to separate them then recombine them with a 3-to-2 converter. I want stop and turn to remain separate.

I talked to the local Ford dealer, they had no idea. I talked to Camping World, and they had no idea.

Can anyone think of a travel trailer or 5th wheel that has separate LED lights for the stop lights and turn lights?

 

Recreational trailers, like mine with LEDs, the circuitry is built into the light housings. But come to think of it, I’ve never run across a RV that has separate/divorced brake and turns. The LEDs only change intensity.

 

I would suggest that, if it is your trailer, to alter the wiring on the trailer to be RV standard.

What it sounds like you have on this trailer is the 7-way 'pole' standard, which outside of the trucking industry very few people use. It's laid out like this:




Very few vehicles outside the trucking industry are wired like this. Your production truck is NOT wired like this, but rather is wired for the standard 7-way round (as shown below):


As you can see, the pin outputs are vastly different, and the brake lights/turn signals are tied together with the RV layout, while the 'pole' layout has them separated.

Since your truck has been built and and all the modules programmed to function with the RV layout, you're going to be better off re-doing the trailer wiring to match.

 

Yes, the semi-truck 7-pin receptacle is different from different from the RV 7-blade receptacle, I agree.

Perhaps I was unclear; this is not how the trailer's existing wiring is configured. The current wiring is configured in the traditional way.

This is a modification I want to make to the existing wiring to separate the brake/turn wire into separate brake and turn wires after the 7-blade connector and before the light fixtures themselves. Does that help clarify my objective? The objective is to have better visibility of the trailer lights by using LED's.

 

So it sounds like you are making the modification to the trailer yourself with respect to putting in LED brake turn lights to replace the existing lights is this correct?

Also, the existing brake/turn lights were separated on the trailer, meaning that you would need to replace both with the LED, and that is your concern. Again, is this correct?

If this is not correct and the LED lights came from the factory, that will change my advice/response.

Finally, what do you use for brakes on the trailer? Electric over hydraulic, electric, surge, no brakes?
The above also changes by response. My understanding from what you said earlier was that you had a flat 4 connector from your trailer. That usually does not use electric brakes

Finally, can you provide the wiring that comes out of the lights that you want to install (please link the lights if you can).



Thanks

 

Correct.


Correct. I will replace both existing incandescent brake/turn lights with separate LED brake and LED turn lights.

 

Honestly, I would set one light up to be the tail light and the other to be the combination brake/turn...

 

I guess I'm not seeing the advantage to what you're wanting to do. I swapped the incandescent bulbs/housings on my trailer over to LED, and it was a direct swap including all wiring. I have had many people follow me on trips and inform me that the LED housings are far superior to the old ones, and there is no question about whether brakes and/or turn signals are active. I did have to make sure my grounds were good, and had to re-do them last fall - if they act up again I will be running a dedicated ground wire to the front.

Seeing as what I thought you were dealing with isn't what you're wanting to address, I guess I have no further advice for you. Good luck.

 

I think I've answered my own question, so I'll post this in hopes of saving someone a bunch of time and money re-inventing the wheel. I tested it on a 2006 Super Duty (non-LED lights), a 2023 Expedition (LED lights), and my 2024 Super Duty Limited (LED lights). It worked flawlessly.

For lights, I used two red True Mods 16"/12 LED Trailer Light Bar Strips and two amber True-Mods 16"/12 LED Trailer Light Bar Strips. They're identical except for the different cover colors. Each light as five wires; ground, yellow, green, brown, and red. Either red or amber can be connected to the flasher and will become sequential turn signals. Without a flasher relay in the circuit, they're running lights (brown wire) or brake lights (yellow, green, or red). They're bright! I used a TecNiq T10-LC00-1 clear light for a back-up light. One was plenty bright for that.

Coming out of the 7-way trailer plug, connect it to a True-Mods ACCEPSACP6001 powered signal relay:
>Brown-to-Brown
>Yellow-to-Yellow
>Green-to-Green
>White-to-White
>Reverse-to-Purple
>Orange-to-Red (this powers the signal relay)
>the other wire powers the trailer brakes, and that doesn't figure into the lighting equation

The True-Mods signal relay says it works on up to 2018 vehicles, but it worked fine on the 2023 Expedition and the 2024 Super Duty Limited.

That gets the vehicle lights working with the LED trailer lights, but does not split the brake light from the turn signals. Enter the non-powered 2-to-3 trailer light converter.

The 2-to-3 trailer light converter splits the brake light power from the turn signal power. I used an Agrieyes converter, and it worked great. Tried a CarroFix LED converter; it made a funny noise and didn't work at all.

The brown wire from the True-Mods ACCEPSACP6001 by-passes the Agrieyes completely and goes straight to the red lensed LED trailer taillights using the light's brown input wire; convenient! Otherwise, on the input side:
>Yellow-to-Yellow
>Green-to-Green
>White-to-White

On the output side of the Agrieyes:
>Yellow-to-Left Turn Amber Sequential Light
>Green-to-Right Turn Amber Sequential Light
>Red-to-Both Trailer Brake Lights

I took it a step further and also wired in the ability to run the whole set-up off a 4-way flat connector as is found on a lot of non-truck vehicles. Pretty straight forward, but you do need a diode in the brown wire circuit to prevent the taillights from coming on when the vehicle is running and the 7-way connector attached.

If you're going to experiment I recommend the Wago Lever-Nuts. Made the connections incredibly quick and easy to connect and disconnect for the trial-and-error phase of putting it all together.

Now I have taillights, bright brake lights, and sequential amber turn signals on the trailer. Exactly what I was looking for, and it works on any vehicle.