Trailer Wiring Harness

Has anyone tapped into the trailer harness yet? I'm adding the Morimoto backup boost bar since backup lights on this truck suck just as bad as they did on my 2018 F150. I added it to that truck and it works amazingly well.

I need to tap into the wiring harness, but am not having any luck finding a wiring diagram for the gen 3. I found one for a 2022 Sequoia which showed the same colors as my F150 - yellow for backup light and white for ground. But I don’t know if that’s a standard. Yes…I know I can always use my Fluke and test it, but I really don’t like to penetrate the insulation on an external harness just to test and let road salts and other crap into the copper.

 

**Edit you need a 5-way plug if you want reverse.

Don't have to splice your wires at all if you spend about $30.00, Basally add a harness that plugs into your current harness and a 4-way and you're off to the races. Get behind the bumper unplug the OEM harness going to the 7-way/4-way and add in the first harness below.

This will add a 4 way plug to your harness with no splicing.

$28 CURT 55384 Replacement Vehicle-Side Custom USCAR 4-Pin Trailer Wiring Harness, Black, 6 x 3 x 9"es

https://www.amazon.com/dp/B0009FJ38Q

Then you can plug in a 4-way and tap/wire it to reverse.

$2 CURT 58030 Trailer-Side 4-Pin Flat Wiring Harness with 12" Wires

https://www.amazon.com/dp/B001GN3BSI?th=1

 

Would you be able to post pics once you get this installed? Definitely interested in adding to my truck as well. TIA.

 

Ohh strike that you need a 5-way plug for reverse.

$41 CURT 56584 Replacement Vehicle-Side Custom USCAR 5-Pin Trailer Wiring Harness , Black

https://www.amazon.com/CURT-56584-C...-side+custom+uscar+5-pin,automotive,90&sr=1-1

Also you could always pull the harness and multi meter the pins on the harness if you're wondering which one is reverse

Or trace it from something like this.

https://www.ajtnt.com/Info/7-Way-Diagram

 

Connector comes off backside or 7 wire connector. Black/white is ground, beige is reverse lights.

Watch the placement, about 1/8in clearance when tail down.

 

I haven’t pulled the plug off the backside yet, but that might work. Was hoping someone had skinned this cat already and could just confirm the colors though.

 

Thanks! The Morimoto bar I’m using goes over the license plate screws. Makes it look like it’s part of the plate frame. Clearance shouldn’t be an issue. I do like how yours looks though.

 

Will do!

 

those are morimoto plate lights

 

I see. I actually like that look a lot. Having had one on my F150, I can’t even imagine how bright two of them are. Just one was bright as ****!

 

Make sure you have the clearance when tail drops as the light will be above the plate, it won't be much. I ended up with double side taping them.

 

So are you saying when you attached it to the plate frame, it still stuck up enough that the tailgate was that close? Or that it was close where you have them mounted now?

 

It's close everywhere. The cannot go any higher where they are now. I did try the plate, either really close or hit. Be really caution on the clearance.
If you have not purchase the light bat yet, may be better getting a flush mount set for the plastic bumper panels for DD /Baja etc.

I had the Morimoto's in the mod pile for another use and decider to use both here.

I am looking into repurposing the front LED fog lights into backups in the plastic fillers in the bumper. Light length is the issue as there is a steel bumper support right in the middle of the fillers

 

Good to know. Many thanks! I’ve already ordered it, so will have to figure it out, but I will definitely take your advice and go slowly.

 

Another option is to use something like the reverse light harness made by diode dynamics. I plan on using a version of this to add in reverse lights that I will then modify to allow them to come on with the vehicle or with a dedicated switch. I like this option as it doesn't cut or splice into any OEM wires.

https://www.diodedynamics.com/stage-series-7-pin-single-output-trailer-wiring-harness.html

 

That is nice. I had added a brake light on my plate with modulator from my motorcycle days to wake the txt'rs which I used the aux power from the trailer to power it. Would have been so much easier to wire on the bench than on the back under the bumper.