HOW TO: Tow Stuff (Hitches, Harnesses and Brakes)

[maguayoko]

(welcome)

All that being said...I believe the only way to be sure all 7 pins work correctly (except for the brake controller, which is a separate install) is to also install the supplemental harness. That's what I did and the 7-pin works perfectly. There is a little trick when installing 4 of the wires of the supplemental unit into the main harness but that is easy enough to work through - I can help with that one here in this thread (one of the posts above mentions a difficulty with it but no one answered his questions)

Let us know if you have questions.

Bob

PLEASE share the ‘trick’ Bob!

 

[maguayoko]

I Installed the main harness no problems...

...so then I get to the supplemental harness -- directions have four wires/pins being installed into the female coupling in the right rear corner of the Liberty (connector positions 1, 7, 8 and 14). Problem is...there are already wires/pins in those locations. The existing wires in the connector are not the same colour as the ones from the supplemental harness.

I can see that with the supplemental harness wires/pins installed, they would correlate to the four lb, pk/db, rd/bk, br/pk wires that I see in the 1, 7, 8, 14 connector positions of the main harness I just installed, and that threaded up to the front of the vehicle and hooked up, would appropriately power the trailer harness.

Question: Do I remove and tape the existing wires in the existing female connector in order to install the four wire/pins of the supplemental harness?

Thanks to any of the "chosen few" who may have already done this.

I'm puzzled...I would have thought the female connector would have had four empty pin-outs that the supp harness would have just slipped into...I'd hate to remove wires that shouldn't otherwise be removed.

Thanks,
Duey

p.s. pics coming

DNA Diesel did u ever figure this out? I have same challenge.
2005 Liberty Renegade 7 pin Mopar and supplemental wiring harness installs w those (4) wires in the rear of the supp harness just dangling.
I have my Tekonsha P3 almost installed and don’t know if it’s going to get power to the 7-pin.
What am I missing?

 

[DavidG91]

Hey Folks. I've seen a lot of posts regarding hitches and wiring and brake controllers for towing over the last month or two and figured I'd try and give back a little to the Jeep community by doing a writeup for all the issues involved. I'll get to some more pics maybe when I'm a little more motivated. So here goes and hope you all enjoy. And as I'll say later, this is all from my own personal research and experience. I'm not a mechanic and don't pretend to be one. This is just a view of the towing world from my point of view. Sorry it's so damn long....



BRAKE CONTROLLER (Gotta stop that beast after you get going!)

Ok lets talk about brake controllers. And this also applies to you folks out there with the tow package already installed! What most people don't realize is that with your seven pin hookup on the back of your Jeep (whether you have the tow package or went to the trouble of installing it yourself) you still have no way to activate the brakes on your trailer! Hard to believe but true. Yes everything else works properly, and the brake "lights" on your trailer even work now. However, without a brake controller installed in your Liberty, there is no signal being sent to the brakes on your trailer. Unfortunately there are a lot of people out there with the tow package that probably think they are using the brakes on their trailer... But all they are doing is wearing out the brakes on their Jeep a whole lot quicker. Now it's up to you to decide if what you are towing is heavy enough to need trailer brakes. Do your research and choose for yourself. But know that most literature says once you get past 1,000 lbs, it's a good idea to have them connected and functional.

Great How To post and discussion. I have an original owner 2005 KJ Jeep Liberty Renegade 4WD V6 with Tow Package.
I plan to tow a small camper trailer; the smallest I found was 18 feet.
I ordered and plan to install a Tekonsha Prodigy 2.
I found the Brake Controller Wire under the driver's kick panel.
https://ibb.co/FBwqfPN
I see the brake pedal harness connector https://ibb.co/S6W9J43 that plugs into the brake pedal plunger box https://ibb.co/j37QYsy.

Does anyone make an adapter that plugs between the connector and the plunger box, bringing out the Brake Lamp wire?

Do you guys go through the firewall to get +12v or tap off something else under the dash? If you go through the firewall, where do you see the grommet or plug?

TIA

 

[DavidG91]

Pull the carpet back under the driver seat and look for the weld seam. Follow that seam up toward the firewall and you'll see a plug. Pop a screwdriver through it and pop it out. It usually is partially covered with a caulk type sealant.

Thanks. Anyone have a currently hosted picture of the firewall plug path?

 

[turblediesel]

There are two plugs people use. Most use the one you can barely see, lower; and one guy used the one that's impossible to see, which is higher.

As you look below the inside edge of the top of the driver's side fender along where the hood release cable runs to the firewall you should get glimpses of where the cable and wiring pass through the firewall if you're using a good flashlight. The plug nearby without anything going through it is the one you want. I think it's about 1.5" in diameter.

From the inside you can almost barely see it if you're upside down and your neck is disjointed like mine. You'll need the strong flashlight which there's no room for. Best to do it by feel with the hood release cable as a start reference.

Tape your wires to the end of a piece of hanger wire and carefully jam it through the grommet.

I put a tekonsha controller in mine and pulled three wires. Two positive wires from the terminals on the end of the power box, and a ground wire to the battery clamp bolt. The ground and one power line are fused inline under the hood. They're for ham radio. The other power wire is for the Tekonsha. It goes to the circuit breaker which I mounted on the metal plate behind the plastic panel in front of the driver's knees. That panel swings down like a glovebox if you pry carefully at the top. I mounted the brake controller in the dash cubby at the front of the console. I used a couple of brackets (originally used to hold stereo components together) in an x pattern to mount it to the cubby and a piece of foam to keep it from dancing up and down.

Good luck with your plug hunt. (Best plug sightings are during an ebbing tide and a waning moon on a tuesday on the east side of the mountain)

 

[DavidG91]

There are two plugs people use. Most use the one you can barely see, lower; and one guy used the one that's impossible to see, which is higher.

Thanks. I see a grommet/plug just below and to the left (from inside) of a large wire bundle going through the firewall behind and above the hood release latch. This is at the far left close to the side/kick panel. From the engine bay, that plug is below and to the right of that large bundle, and very close to that corner. https://ibb.co/gt1wktq. I could not really tell if that is a metal plug or a rubber one and I have not yet tried to push the wire hanger or screwdriver through it. Actually it might be plastic.

I see the recommendations for a 20 or 30 A breaker on the 12v source. 20A at 4-6 feet should be 14 gauge wire, 30A should be 12 or 10 gauge. Etrailer says https://www.etrailer.com/question-241469.html

Tekonsha uses 10 & 12 gauge wire on their brake controllers. They use 10-gauge for the 12V [black] and output [blue to trailer brakes] and-12 gauge for the red [brake switch input] and white [ground].

so that is what I will use.

white is ground, black is 12 volt power in (this is the wire that gets the circuit breaker), red is input from the brake switch, and blue is output to the trailer brakes.

 

[DavidG91]

Thanks. I see a grommet/plug just below and to the left (from inside) of a large wire bundle going through the firewall behind and above the hood release latch. This is at the far left close to the side/kick panel. From the engine bay, that plug is below and to the right of that large bundle, and very close to that corner. https://ibb.co/gt1wktq. I could not really tell if that is a metal plug or a rubber one and I have not yet tried to push the wire hanger or screwdriver through it. Actually it might be plastic.

I see the recommendations for a 20 or 30 A breaker on the 12v source. 20A at 4-6 feet should be 14 gauge wire, 30A should be 12 or 10 gauge. Etrailer says https://www.etrailer.com/question-241469.html

so that is what I will use.

You can much more easily see the pedals and wiring underneath the dash by swinging down and removing the plastic piece under the steering wheel. It has two pin connectors at the top and hinges at the bottom.
https://ibb.co/3z9Jnd0

After popping it out from the top, it swings down, then you can slide it to the left and remove it.
https://ibb.co/RTSML6W

I used a flathead screwdriver to pop out the plug next to the corner.
https://ibb.co/KX5CG1K
https://ibb.co/T4jcBkH

I used a barrel splice to connect the brake controller's blue output wire to the Jeep's red brake controller wire behind the driver kick panel, and a quick splice snap connector to connect the red brake controller stop lamp wire to the white/tan second wire on the brake pedal harness.