Trailer Wiring

[meingraham]

I presume that with the growing popularity of the non permanent options, Kia did this so you can choose. They probably didn’t connect that incab harness so you don’t have live wires dangling behind the dash that aren’t in use.

I think this is probably right. When I inspected the installation guide, the instructions showed taking the driver's area panels off in order to access the connector that this harness plugs into. Based on what you posted, one then connects the brake controller to the exposed leads of the harness. This then provides the braking signal required which is "pre-wired" back to the 7-connector plug.

I've never done any substantial towing other than the occasional U-Haul or flatbed trailers. Always with a 4-pin flat and never with any additional braking control. I had already looked into the required adapter to convert from 7 to 4 (or 5) and will probably invest in one of those to keep with the ball mount in order to be prepared for those occasions.

I am planning on purchasing a small camper which is the reason I got the car with the factory towing package. I'll cross the brake controller issue if and when that is needed.

Thanks for your reply @NCTelly. That's the information I needed. I can now put this bit into my brain's archive (i.e., a note in Evernote ).

Mike

 

[FHFR3]

I did the install as you described it. Thank you. I cut the yellow/back wire and connected the reverse light wire with the yellow/black.
works like a champ. Now I can back up the boat trailer.

I noticed the pin 1 wires are connected, red to white. Is this battery hot? Is the fuse in place or is the slot empty? On off with the key? Thanks!

 

[FHFR3]

Dumb question, but did you all remove the wheel and cover to access the harness?

I did mine with the wheel on, laying under the car. Just up on jack stands

 

[psor]

Hi @meingraham,

Is it possible to post a picture of this extra harness you have. I am very interested to see it. And mayby the instructions about connecting it. I am doing a lot of research around connecting brake controllers on my new 2021 Telluride and you would be very helpful. Thanks.!

Patrick.

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[FHFR3]

I just got my recall notice on the Brake lights not working on the trailer when the smart cruise applies the brakes. Going next Monday to have the additional harness added before I add the 7pin trailer harness just to avoid questions

 

[Midtown10105]

I just got my recall notice on the Brake lights not working on the trailer when the smart cruise applies the brakes. Going next Monday to have the additional harness added before I add the 7pin trailer harness just to avoid questions

Please let me know how that goes. I just received the recall notice and will plan on going on the next oil change. Which 7 pin harness did you get?

 

[FHFR3]

Please let me know how that goes. I just received the recall notice and will plan on going on the next oil change. Which 7 pin harness did you get?

Will do. It was the 4 to 7 pin conversion from Hopkins at Tractor Supply. Let you know when I get it installed.

 

[Hunyutti]

I just used this info to install a 5-pole adapter. Thanks!

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[FHFR3]

Well they did the trailer brake light recall and it took about an hour for that and the oil change service. They never said a word about my adding the fifth wire for the back up lights. I will do the 4 pin to 7 pin connector swap this weekend. Let you know how that goes.

 

[Rom58]

Yes, I believe that is a four-pin harness, in case your trailer only has that connector. Electric brakes should work with the 7-pin, but of course you want to test the trailer brakes to confirm.

The seven pin trailer plug is wired, but it is not wired to a brake controller, you will need to use the pig tail that comes with the unit, i found mine in the glove compartment. If you look under your dash right behind the fuse box ( to your lower left in the drivers seat) you will find the mating plug. You need to provide the brake controller. I installed a Tekonsha P3, the 4 wires feed the brake controller 12v power, a ground wire, a Brake output for electric brakes and a brake light also. If you use the brake controller manually it will send a brake light signal as well.
This is a standard brake controller as many are, I pulled this controller out of my infiniti QX60 that I replace with my New Telluride. Without adding a brake controller you will have the standard 4 pin wiring, you will also have the 12v charge line and the back up wire is live. If you plan to pull a trailer over 3k you need to have a brake controller, as trailers rated at 3K and above have to have brakes, does not mean they have to be electric, as my 6000 lbs boat has hydraulic surge brake, but it does have brakes. Now this is the New 2021 Telluride that comes with the seven pin plug, not the 4 pin. Hope that helps a little

 

[harrisw5]

Great info. Used it to turn my 4-flat dealer install into a 5-flat, such that I can back up my trailer. Thanks for the pics and details.