Help adding 7 pin to ‘17 XLT 4x4

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The6ofus

The6ofus

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There is a adapter 7 pin to 4 pin that plugs right into the 7 pin. I wouldn't keep changing out harnesses. Plus when you change it I would silicone caulk it so its all nice and waterproof.

Good point! I have seen those on etrailer as they were trying to answer my questions.
 

Black

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Get this wiring kit and you will have the 7 pin and 4 pin. No need for an adapter. I have a 7 to 4 pin adapter for my Z71 and it is just another thing to worry about.
https://www.etrailer.com/Wiring/Curt/C57674.html

I would cut the 4pin connectors off and splice all the wires together as opposed just to the plugging the new Curt 4 pin to factory 4 pin.

I know you are short on time but would be nice if someone with the factory 7 pin would show the harness behind the wheel to see if one could just buy the factory 7 pin harness and plug it in there. Since the Aux power is a fused hot wire they may have terminated it there for safety reasons.
Why they did not just terminate the trailer brake wire there too I have no clue. Also does not explain why they did not run the reverse light along with the trailer brake wire too.
 

theoldwizard1

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It is odd that this truck has a Class IV hitch, ...
Technically, I think it is a Class III.

The HD tow package also has an different radiator than we do.
Yes ! If you want the HD radiator it is a "drop in" replacement. The auxiliary transmission cooler might take a couple of hoses, tubes, clamps.


My daughter had this done on her '12 Expedition. The place that sold her the trailer actually ran a separate power wire from the battery to the dash and brake controller and then to the 7 pin connector. Clearly not all of the necessary wiring was in place.
 
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The6ofus

The6ofus

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I’ll have to post the hitch details. It reads class 4 as I recall but wouldn’t surprise me with all the other stuff being weird that it’s a 3. The 3 will be sufficient for my 2200# camper.

566cedce8248beecc0591bc5a74ddf0b.jpg

I’m currently at my local dealer getting a 2nd key made and stopped in the parts department. The gentleman there said the pigtail I’m seeing on the frame rail is “without a doubt” in the storage holder and “is definitely” for the 7 pin. He swears they’ve helped about a dozen other 15-17 Expedition owners with the same question. The service department offered to confirm it for me for the low, low price of $135! [emoji44] I declined for now and will dove into it in the next few days.
 

CaptOchs

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I wouldn't think a popup would "require" a 7-pin. Most of the older popups are 4-pin. I suppose it's probably to charge the trailer's battery and possibly electric brakes.

Personally, I think if I was in your situation, I'd clip off the 4-pin (they corrode easy anyway) and make my own 7-pin female plug. You're under the weight limit for required brakes; except in the nanny states. http://www.brakebuddy.com/towing-laws.html I've got the 2003 with the 5.4L and I have towed many trailers/boats that are in the 2000-3000# without brakes. The truck's brakes were more than sufficient in braking. If you were towing with a different vehicle that has a max tow of 3000#, that would be a different story.
 

brhulen

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The first time your trailer sans brakes "comes around" when braking suddenly on a wet or slick road will make you a believer! I know there are many folks who will dispute the necessity of such a useless item and who have pulled thousands of miles with no mishaps but all it takes is once! If nothing else consider the cost of the body repair to your tow vehicle and trailer after your "incident". And of course there's all those pesky litigious drivers who had the audacity to be struck by your trailer or tow vehicle when you lost control. It's true when pulling a lightweight trailer the tow vehicle probably has adequate brakes to stop. Understand though the trailer is connected by a ball and naturally wants to swing to one side or the other under sudden stops or if your trailer fire blows out.
 
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The6ofus

The6ofus

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Ah! I love the Internet. I appreciate the input but I will be using a seven pin. Thanks!
 

mquick5

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My 17 has the four pin, and that extra wire. If you look at first picture you can still see the writing on the tag.bbf88e8d33cb8cd3fd8d1016f5691da6.jpg9956ea9d0b68c32ca97bca5fb65076f5.jpg

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