Trailer wiring harness install

RagnarKon

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Also curious about this install. Currently have trailer tow on order, but I'll drop it if it makes my build appear faster.

My father did it on his Bronco, but of course he didn't take any pictures. When I asked him about it the most he said was "Ah yeah, it was easy, pop out the trim pieces and route the cable where it needs to go.".

"Hey dad can you go into a little more detail?"

"I don't know what there is to say... pop out the trim pieces, put the cable in, put the trim pieces back. Done."

"Well where does the cable go?"

"To the back of the truck, where else would it go?"

Thanks dad... big help.
 

De Brus

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Which method? If you buy the wiring box, you just un plug a harness behind the trim panel and plug the box in between. Then run power to the battery (or hot lead behind trim if you know how to test). Now route the trailer plug to the hitch.
 
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iwantabasebronco

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Also curious about this install. Currently have trailer tow on order, but I'll drop it if it makes my build appear faster.

My father did it on his Bronco, but of course he didn't take any pictures. When I asked him about it the most he said was "Ah yeah, it was easy, pop out the trim pieces and route the cable where it needs to go.".

"Hey dad can you go into a little more detail?"

"I don't know what there is to say... pop out the trim pieces, put the cable in, put the trim pieces back. Done."

"Well where does the cable go?"

"To the back of the truck, where else would it go?"

Thanks dad... big help.
Yeah I have received and harness ready to go. Just need my whip. I’m sure I’ll figure it out and post pictures.
 
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iwantabasebronco

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Which method? If you buy the wiring box, you just un plug a harness behind the trim panel and plug the box in between. Then run power to the battery (or hot lead behind trim if you know how to test). Now route the trailer plug to the hitch.
The one from the Ford accessories site requires some splicing into the brake lights
 

De Brus

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RescueCheckPT2

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Also curious about this install. Currently have trailer tow on order, but I'll drop it if it makes my build appear faster.

My father did it on his Bronco, but of course he didn't take any pictures. When I asked him about it the most he said was "Ah yeah, it was easy, pop out the trim pieces and route the cable where it needs to go.".

"Hey dad can you go into a little more detail?"

"I don't know what there is to say... pop out the trim pieces, put the cable in, put the trim pieces back. Done."

"Well where does the cable go?"

"To the back of the truck, where else would it go?"

Thanks dad... big help.
Is your father Ron Swanson?
 

BudgetBronco

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da_jokker

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Wait this is for a 4 wire right. I thought that was just a simple pigtail legit stuck in between your tail light and the wiring harness.

Dang.. I added a four pin to my Wrangler you're literally took 10 minutes... You popped the tail light out with two screws, plug the pigtail in, and you were done.

If you're going to go through that much trouble, why not just run the 7 pin.
 

Panzer948

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Wait this is for a 4 wire right. I thought that was just a simple pigtail legit stuck in between your tail light and the wiring harness.

Dang.. I added a four pin to my Wrangler you're literally took 10 minutes... You popped the tail light out with two screws, plug the pigtail in, and you were done.

If you're going to go through that much trouble, why not just run the 7 pin.
Hi, I am a bit confused by this as well and maybe he can answer. I only have the 4-Pin installed (after delivery by the dealer as a Ford accessory). Budget Bronco is right in that they didn't have a 7-pin available but now I realize I need one so I can tow some light campers. Ford Service Manager indicated the 4 Pin was $$ labor since they had to run it to a connector up front, remove panels, etc. (which this vid also portrays). Correct me if I am wrong but the way his 4 Pin is wired (which I think is similar to my Ford product), with the exception of the brake controller, you nearly have all the wires in place needed for the 7 Pin. Thus, one could pick up a 4 pin to 7 pin adapter and use this 12 volt positive lead for the 7 pin wire used to charge your trailer battery.

Long story short, I use to think that a 4-Pin didn't need a positive lead from the battery so I am hoping they are doing this to future proof for 7 Pin. Just a bit confused why trailer light controls need that when all the connections should be in the taillights. But if Ford did run that positive wire all the way to the battery on my setup too, then they may have saved me the trouble of having to do that when I pickup a 7-pin (on order today).
 

Ksjrb03

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Hi, I am a bit confused by this as well and maybe he can answer. I only have the 4-Pin installed (after delivery by the dealer as a Ford accessory). Budget Bronco is right in that they didn't have a 7-pin available but now I realize I need one so I can tow some light campers. Ford Service Manager indicated the 4 Pin was $$ labor since they had to run it to a connector up front, remove panels, etc. (which this vid also portrays). Correct me if I am wrong but the way his 4 Pin is wired (which I think is similar to my Ford product), with the exception of the brake controller, you nearly have all the wires in place needed for the 7 Pin. Thus, one could pick up a 4 pin to 7 pin adapter and use this 12 volt positive lead for the 7 pin wire used to charge your trailer battery.

Long story short, I use to think that a 4-Pin didn't need a positive lead from the battery so I am hoping they are doing this to future proof for 7 Pin. Just a bit confused why trailer light controls need that when all the connections should be in the taillights. But if Ford did run that positive wire all the way to the battery on my setup too, then they may have saved me the trouble of having to do that when I pickup a 7-pin (on order today).
What your missing is the fact the Bronco, and most modern vehicles, use PWM for the tail lights. This is not a standard 12v circuit you can just tap for trailer lights like the “old days”.

The aftermarket 4 pin modules all need 12v to power the PWM converter module and send 12v to the 4 pin trailer plug. The 7 pin will be very hard to add to a Bronco without tow package for the same reasons, plus the need for running light, reverse, and brake signal.
 

da_jokker

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What your missing is the fact the Bronco, and most modern vehicles, use PWM for the tail lights. This is not a standard 12v circuit you can just tap for trailer lights like the “old days”.

The aftermarket 4 pin modules all need 12v to power the PWM converter module and send 12v to the 4 pin trailer plug. The 7 pin will be very hard to add to a Bronco without tow package for the same reasons, plus the need for running light, reverse, and brake signal.
Ah...so it's because of the LED tailights then?

So etrailer has a universal 7 pin harness that sounds like it was designed to tap into a 4 pin and the 1 wire (for charging is ran to the battery) and 1 wire (for brake signal) is ran to the brake controller.

So it would seem to me that if you ran a 12v wire from the battery to the back (which actually may come in handy from lots of things), the 4 pin "hot" and the 7 pin "universal hot" could share. Then you only need to run 1 extra wire up to under the dash for something like the P3 Brake controller.

Or maybe I'm not thinking straight. I'm starting to think the best way to do this is to run a pretty good gauge hot wire to the back area, maybe to a small fused power distribution box, can I use it to bring good battery voltage to the rear of the Bronco for all your needs.
 

Ksjrb03

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Ah...so it's because of the LED tailights then?

So etrailer has a universal 7 pin harness that sounds like it was designed to tap into a 4 pin and the 1 wire (for charging is ran to the battery) and 1 wire (for brake signal) is ran to the brake controller.

So it would seem to me that if you ran a 12v wire from the battery to the back (which actually may come in handy from lots of things), the 4 pin "hot" and the 7 pin "universal hot" could share. Then you only need to run 1 extra wire up to under the dash for something like the P3 Brake controller.

Or maybe I'm not thinking straight. I'm starting to think the best way to do this is to run a pretty good gauge hot wire to the back area, maybe to a small fused power distribution box, can I use it to bring good battery voltage to the rear of the Bronco for all your needs.
In general, yes it is due to the LED lights. But the base tail lights with bulbs also use PWM.

The brakes are your problem on a 7 pin, there is no easy way to connect a brake controller without the factory tow package. There is a guy who has been working on it, dont remember his name but there are some long threads on aftermarket tow. Search for his posts and info if your needing 7 pin.
 

da_jokker

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In general, yes it is due to the LED lights. But the base tail lights with bulbs also use PWM.

The brakes are your problem on a 7 pin, there is no easy way to connect a brake controller without the factory tow package. There is a guy who has been working on it, dont remember his name but there are some long threads on aftermarket tow. Search for his posts and info if your needing 7 pin.
I'll have to look into that. There's so many duplicate threads it's hard to read them all. I would assume that there's a switch by the brake pedal that you would tap into for that universal wire signal.... Unless they've gotten so advanced now that they just read off the pressure of the master cylinder and don't even need a switch on the pedal anymore.
 
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