Trailer wiring?

[Clint in KY]

I purchased an '03 Liberty Sport yesterday and while it has a Class III receiver hitch it has no wiring. Researched a harness and found three different types:

1.) Two T connectors to attach between the tail lights.
2.) As above but with a Converter
3.) Similar but has a wire that must be connected at the battery.

I tow a boat and a utility trailer both with the 4 Pin Flat plug.

Which one do I need and why?

side note: I can not believe that Jeep did not put a single connector under the bumper like the last two Fords I have had to make this job so much easier.

 

[Cardhu]

http://www.jeepkj.com/forum/f202/how-tow-stuff-hitches-harnesses-brakes-26895/

Above link has most of the info. Most recomend the mopar stuff, i've done fine with the aftermarket 4 pin flat to the battery for towing my boat. just make sure you get one that is for your vehicle and it just clips into the tail light assembly.

The ones that require power from battery just are rated for more current usually. Really depends on what your towing.

 

[tommudd]

I purchased an '03 Liberty Sport yesterday and while it has a Class III receiver hitch it has no wiring. Researched a harness and found three different types:

1.) Two T connectors to attach between the tail lights.
never
2.) As above but with a Converter
NO
3.) Similar but has a wire that must be connected at the battery.

I tow a boat and a utility trailer both with the 4 Pin Flat plug.

Which one do I need and why?

side note: I can not believe that Jeep did not put a single connector under the bumper like the last two Fords I have had to make this job so much easier.

There are ones that connect inside the right rear quarter panel, run them on all 3 of the KJs here

 

[nohitter64]

I used what Tom mentioned. I picked it up on etrailer.com and ran it through a rubber grommet in the floor then over to the receiver. It works great.

 

[Clint in KY]

http://www.jeepkj.com/forum/f202/how-tow-stuff-hitches-harnesses-brakes-26895/

Above link has most of the info.

The ones that require power from battery just are rated for more current usually. Really depends on what your towing.

Thanks for the link - BUT - I am still confused about the one with the converter. See below.

I used what Tom mentioned. I picked it up on etrailer.com and ran it through a rubber grommet in the floor then over to the receiver. It works great.

E Trailer now offers 3 models, all of which connect behind the tail lights:

One by Curt - with the converter
One by T One with the wire to the battery
and one by Hopkins without the converter.

Both my trailers have LED lights so I do not need the one with the wire to the battery as the LED lights draw very little current.

So that leaves me with With or Without the converter. My first reaction is to get the one without the converter as Henry Ford said "Any part you can leave out will never fail." But I am curious why they would offer it if it wasn't needed.

Thanks

 

[Ohio-white-kj]

It's not so much the amp draw (though that is the part of the original Jeep design) it's that the KJ has separate stop and turn signals. The converter works to give an output for trailers with combined stop/turn.

You can either use a converter - or wire a separate turn signal for all your trailers.

The Mopar converter thingy uses relays in that kick panel to achieve it, some of the aftermarket ones do it with an electronic module "thingy".

I've had a couple vehicles I added them, both aftermarket and OEM. I even built one myself from relays once FWIW.

If I was recommending it to others I'd say OEM, If I was doing it myself, today, being cheap and lazy, I'd probably buy a converter

It depends on your skill level / understanding.

edit: I took a quick look at both those, either looks OK, and built well. ME - I'd go for the powered one, but there is the hassle of extra wiring. Kind of just in case

Thanks for the link - BUT - I am still confused about the one with the converter. See below.



E Trailer now offers 3 models, all of which connect behind the tail lights:

One by Curt - with the converter
One by T One with the wire to the battery
and one by Hopkins without the converter.

Both my trailers have LED lights so I do not need the one with the wire to the battery as the LED lights draw very little current.

So that leaves me with With or Without the converter. My first reaction is to get the one without the converter as Henry Ford said "Any part you can leave out will never fail." But I am curious why they would offer it if it wasn't needed.

Thanks

 

[TwoBobsKJ]

I know the temptation is to use one of the lower cost aftermarket harnesses, but I've never been a fan of tapping into the rear lighting system - especially on modern vehicles with so much interfacing between the computer and lighting control. Even if you have to insert plugs rather than splice you're still introducing a failure point in an exposed part of the Jeep.

The OEM/Mopar harness IS more expensive - but if you go with the 4-flat harness it is literally less than 30 minutes to install. Totally plug-n-play using attachment points that are already built into your Jeep and the grommet that's under the cargo floor carpet.

Here's a link to a Mopar harness. There are two listed; the first one is for the 7-pin round harness and based on the price I'd say they've included what Chrysler calls a "supplemental harness" to integrate battery power and trailer brakes into the harness at the hitch. In my case I installed the 7-pin because I'd rather be over-prepared than under. And sure enough I've towed trailers with a 7-pin hookup and was glad I had it. Here's another site with better prices.

However, if you're SURE you're never going to need the 7-pin, scroll down a little bit and get the 4-flat Mopar harness. About $100 cheaper and you'll be ready to hook up a trailer and go towing inside an hour. You don't need to pull the rear taillights and then try to figure out which wire is brakes, which is backup, etc. Pull back the carpet and the right-rear quarter panel, plug in the harness, feed it through the grommet, clip it to the underbody and attach it to the hitch. Done.

EDIT: Found this one on eBay. It's the 4-flat and says it's new but may not have everything in the kit. But it's half the price of the one linked above.

Question: Does your hitch have the box for attaching the wire harness? If not it is probably a hitch installed to satisfy a recall. If there isn't a box on it then you'll need to find/install one to accommodate the trailer harness. Should look like this:

You must be registered for see images

Let us know if you have any questions. I've installed a few hitches and harnesses - some worked a lot better than others :waytogo:

Bob

 

[Clint in KY]

I know the temptation is to use one of the lower cost aftermarket harnesses, but I've never been a fan of tapping into the rear lighting system - especially on modern vehicles with so much interfacing between the computer and lighting control. Even if you have to insert plugs rather than splice you're still introducing a failure point in an exposed part of the Jeep.

The OEM/Mopar harness IS more expensive - but if you go with the 4-flat harness it is literally less than 30 minutes to install. Totally plug-n-play using attachment points that are already built into your Jeep and the grommet that's under the cargo floor carpet.

Here's a link to a Mopar harness. There are two listed; the first one is for the 7-pin round harness and based on the price I'd say they've included what Chrysler calls a "supplemental harness" to integrate battery power and trailer brakes into the harness at the hitch. In my case I installed the 7-pin because I'd rather be over-prepared than under. And sure enough I've towed trailers with a 7-pin hookup and was glad I had it.

However, if you're SURE you're never going to need the 7-pin, scroll down a little bit and get the 4-flat Mopar harness. About $100 cheaper and you'll be ready to hook up a trailer and go towing inside an hour. You don't need to pull the rear taillights and then try to figure out which wire is brakes, which is backup, etc. Pull back the carpet and the right-rear quarter panel, plug in the harness, feed it through the grommet, clip it to the underbody and attach it to the hitch. Done.

Thanks - that gives me the real part number and I found a few different sites that have it at somewhat lower prices.

Question: Does your hitch have the box for attaching the wire harness? If not it is probably a hitch installed to satisfy a recall. If there isn't a box on it then you'll need to find/install one to accommodate the trailer harness. Should look like this:


Let us know if you have any questions. I've installed a few hitches and harnesses - some worked a lot better than others :waytogo:

Bob

My Liberty does not have the box to hold the connector. A search of Recalls shows Chrysler has inspected the hitch in accordance with the recall. I am going to assume (always dangerous) that the hitch is aftermarket. I crawled under it and got a number off it but came up empty on a google search of the number. I am also going to assume that the PO had the hitch installed to use a carrier to carry bicycles or some such as there is no wiring present. I will price the harness at my local Jeep Dealer and get it there if it is close to the online price as I like to shop local when I can.

 

[sota]

2007 Jeep Liberty Custom Fit Vehicle Wiring - Hopkins

this. all day. every day. nothing else makes any sense. I installed mine in the parking lot of the dealership the night I bought it, along with the trailer hitch. (kind if needed to since I had to tow my car home. )


https://www.etrailer.com/Wiring/Hopkins/HM40975-11998.html

also this.

 

[Clint in KY]

2007 Jeep Liberty Custom Fit Vehicle Wiring - Hopkins

this. all day. every day. nothing else makes any sense. I installed mine in the parking lot of the dealership the night I bought it, along with the trailer hitch. (kind if needed to since I had to tow my car home. )


https://www.etrailer.com/Wiring/Hopkins/HM40975-11998.html

also this.

This is the harness I plan to get (or one very similar). I also plan to get a bracket to hold the connector, but just the Flat 4 not the Round 7.

One question: I read where the harness comes up through the floor through a hole (found the hole) but where in the vehicle does it connect? I have found no reference to where the vehicle harness connector resides.

 

[tommudd]

This is the harness I plan to get (or one very similar). I also plan to get a bracket to hold the connector, but just the Flat 4 not the Round 7.

One question: I read where the harness comes up through the floor through a hole (found the hole) but where in the vehicle does it connect? I have found no reference to where the vehicle harness connector resides.

Inside the left rear quarter panel
Behind the little storage space on the left side
remove interior panel to get in there, can see the rubber plug then

 

[TwoBobsKJ]

Inside the left rear quarter panel
Behind the little storage space on the left side
remove interior panel to get in there, can see the rubber plug then

Tom means the storage area is actually in the right rear quarter panel - but I can be a smart **s today cuz I'm on pain meds from back surgery :happy175::happy175:

Sorry Tom :emotions34: arty52:

Bob

 

[Clint in KY]

I just ordered the same type harness you used from ETrailer.

Thanks for your help.

 

[Clint in KY]

Tom means the storage area is actually in the right rear quarter panel - but I can be a smart **s today cuz I'm on pain meds from back surgery :happy175::happy175:

Sorry Tom :emotions34: arty52:

Bob

Actually I have read posts on a few boards that say if you can't find it on one side to look at the other side. So I guess they ran it both ways on the assembly line.

I have spent a lot of time on the forums as I have only had this Jeep (my first Jeep) for about 3 days and have a few issues, such as the lack of trailer wiring to address.

The next issue is the lack of driving lights. Here in the Heartland good lights is one key to not collecting deer on the hood and windshield this time of year.

Then to replace the tacky aftermarket wheels that came on it when I bought it. Chrome wheels on a Jeep - really???

 

[tommudd]

SORRY :shrug:
its the right side:emotions34::favorites68:
Was talking to my wife this morning while typing that, so I'll blame her. With them driving on the wrong side of the road, steering wheel on the wrong side etc over there got be all backwards:happy175:

 

[Clint in KY]

I received my Hopkins #42475 harness from ETrailer yesterday and installed it this morning. No real hiccups. The one thing I want to know is if Jeep has a guy who goes around sharpening the edges of all sheet metal so no matter where you stick your hand it comes back bleeding.

 

[Toymanjeep]

Does the Mopar harness come with good instructs ?

 

[TwoBobsKJ]

Does the Mopar harness come with good instructs ?

Back in the Daimler Chrysler days when our KJ's were built they used "universal" language in their instructions - which means no words just pictures :favorites68:

That said, the pictures explain the installation pretty clearly. It makes more sense when you move the right rear interior quarter panel out of the way. You'll see the relays in there into which you plug the trailer harness. If you're buying the 7-pin harness and DON'T have an EVIC console then you'll need to get the "supplemental harness." If you're installing the 4-flat harness then it will take you about 30 minutes to install and you'll only be working in the cargo area of the Jeep.

If you can assemble Christmas gifts under extreme pressure on Christmas Eve then you can do this arty52:

Bob

 

[Clint in KY]

The instructions were good enough,with the only inaccuracy being they said to remove a cargo tie-down hook that did not exist.

 

[Toymanjeep]

Thanks for the replies. Sounds doable, until I read Bobs closing sentence, that makes it purddy tuff !:whip: