Trailer wiring harness self-installation

JuJu

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Has anyone installed the wiring for the trailer wiring harness yet? I just received my receiver and the harness, but their is absolutely no instructions on where to begin. I know it isn't a terribly complicated thing to do, but it would have been nice for just a little bit of direction; like where is the best path for wires and such. The receiver hitch install looks very simple, especially with the instructions and will likely take just a few minutes having it on a lift to work on. The wiring however...well Ford didn't include anything. Will be installing this week and will give some feedback, just wondering if anyone might have some advice to get me in the right direction.
As a picture can sometimes be worth 1000 words. Here's a picture of my install. I opted to remove the left side covers and install the converter in between the inner fender well behind the tail light. I cut the wires off equally and attached 5ft tails on all of them. I ran all the wires inside after having taped them about 3 feet from the controller twice over. There's a grommet you can cut or do like I did and cut a clean square with side cutters for your wires and black silicone them in place once everything is mounted with numerous zippy ties.

I opted for a srictly flat 4 lights with ZERO plans to ever need a tow controller.

I cut the hot wire out of the plugs intendend for the factory trailer brake controller and replaced the 30A fuse with a 15A one to protect the converter. 15A x5 That red wire is hot and is actually connected to what is a black wire at the converter.

I cut the brown paking light wire right at the plug. There's a suitable grounding spot behind that 8mm bolt above the rear left fender.

Under that kick cover on the Left rear there's an exposed section where you can tap the Left and Right tail you need for the converter. The green is right and yellow is left. Again numerous zippy ties.

There's an installation instructions floating around. I based some of my install on that. It was comforting to have access to that resource.

Overall an involved job. Easy enough honestly. I won't bore you with all the warnings. There might someday be another less invasive harness for these. But this is tried and tested.

In my opinion it's not a hack job. Everything shrink tubed over soldered points.

Left Rear Fender.jpg


Left Rear Kick .jpg
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WildWillie

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As a picture can sometimes be worth 1000 words. Here's a picture of my install. I opted to remove the left side covers and install the converter in between the inner fender well behind the tail light. I cut the wires off equally and attached 5ft tails on all of them. I ran all the wires inside after having taped them about 3 feet from the controller twice over. There's a grommet you can cut or do like I did and cut a clean square with side cutters for your wires and black silicone them in place once everything is mounted with numerous zippy ties.

I opted for a srictly flat 4 lights with ZERO plans to ever need a tow controller.

I cut the hot wire out of the plugs intendend for the factory trailer brake controller and replaced the 30A fuse with a 15A one to protect the converter. 15A x5 That red wire is hot and is actually connected to what is a black wire at the converter.

I cut the brown paking light wire right at the plug. There's a suitable grounding spot behind that 8mm bolt above the rear left fender.

Under that kick cover on the Left rear there's an exposed section where you can tap the Left and Right tail you need for the converter. The green is right and yellow is left. Again numerous zippy ties.

There's an installation instructions floating around. I based some of my install on that. It was comforting to have access to that resource.

Overall an involved job. Easy enough honestly. I won't bore you with all the warnings. There might someday be another less invasive harness for these. But this is tried and tested.

In my opinion it's not a hack job. Everything shrink tubed over soldered points.

Left Rear Fender.jpg


Left Rear Kick .jpg
Thanks for the pictures and the information. We began today, only getting to work over the lunch hour while he has to students, and will finish it up tomorrow. It's definitely more than just a splice here and a splice there. We followed the linked sheets here from this thread, which are very helpful, but also lacking in some regards.

The grommet in firewall seemed to be a mile thick, so it was tough getting through. The grommet behind tail light is much thinner, but shouldn't be cut where the direction show. It shows the spot that is like the spine (2 inches thick) vs off-centered where 1/4 or less thick. It could also be stated somewhere that to remove the tail light requires dismantling what felt like the entire corner of Bronco. The process was made much tough since its currently sitting on a lift (waiting wheel powder coating and tires) which limited workspace. It should be noted that the kick panel is held on by 2 bolts (not that easily visible) while the entirety of the interior molding simply snaps in place. Overall, not terribly complicated to install, but some things can be troublesome. Ford could have easily done during manufacturing (or at least made it a bit simpler), but if you are capable of running simple tools and putting things back together after deconstruction, it isn't too much.

Snapped a few pics of the places I ran into problems following linked directions in this thread. Will get this posted tomorrow after finishing up.
 

Riverafter

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You capable of taking the rear trim panels off and tapping a few wires? Not trying to sound like an arse but needing to know your level of skill. Other thing, you have a 2 door, I will need to see behind the driver side rear cargo area panel to see if the wiring is there like the 4d I just did.

There's a small panel that pops off, need to look down in there and see if this set of 3 connectors is there. If so, we GTG.


IMG_2004.JPG
As someone about to begin this wiring nightmare, I have questions myself.
I bought the harness from Ford, but seeing this picture, are the three pig tails shown in this photo, usable for the taillights or are they something else?
 

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As someone about to begin this wiring nightmare, I have questions myself.
I bought the harness from Ford, but seeing this picture, are the three pig tails shown in this photo, usable for the taillights or are they something else?
You can use one of them to get power to the tail light converter (2 wire plug with larger gauge wires). The larger plug has a brown wire that can be used for park lights. The ground is just above the connectors, just be sure to not overtighten this and snap the stud.

You will still need to tap the left and right signal wires if you have halogen lights (blue wire on the converter will go with the ground wire as the stop signal is picked up on the turn circuit). If LED, blue will get hooked up to the stop wire on the left side.

Before you put your panels back on make sure the 4 pin is working. A couple of us have used scotch locs on the wires and, due to the small gauge, didn't get a good bite through the insulation. I would suggest getting a 15A fuse to replace the 30A or 40A in the box under the hood if you are going to get power at the back connector.
 

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This is why I decided to purchase/install the hitch myself (have the Curt hitch sitting on the table right now) but get the wiring harness from Ford and let them install. I'll burn a few hundred bucks of my Fordpass points but I think in this case it's worth it.
 

GoTigersGoBronco

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I bought the Ford towing harness (that’s presumably for multiple Ford models). There are some after market companies that make no-splice wiring harnesses for the Bronco Sport. I think we’ll see those in the next few months. They may be easier for some folks.
 

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Thanks for the pictures and the information. We began today, only getting to work over the lunch hour while he has to students, and will finish it up tomorrow. It's definitely more than just a splice here and a splice there. We followed the linked sheets here from this thread, which are very helpful, but also lacking in some regards.

The grommet in firewall seemed to be a mile thick, so it was tough getting through. The grommet behind tail light is much thinner, but shouldn't be cut where the direction show. It shows the spot that is like the spine (2 inches thick) vs off-centered where 1/4 or less thick. It could also be stated somewhere that to remove the tail light requires dismantling what felt like the entire corner of Bronco. The process was made much tough since its currently sitting on a lift (waiting wheel powder coating and tires) which limited workspace. It should be noted that the kick panel is held on by 2 bolts (not that easily visible) while the entirety of the interior molding simply snaps in place. Overall, not terribly complicated to install, but some things can be troublesome. Ford could have easily done during manufacturing (or at least made it a bit simpler), but if you are capable of running simple tools and putting things back together after deconstruction, it isn't too much.

Snapped a few pics of the places I ran into problems following linked directions in this thread. Will get this posted tomorrow after finishing up.
Did the base model have the plugs in the back under the panel like other trims that have towing option?
 
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