Another towing question

[TheSauce05]

I've been doing some research on this site and others on installing a brake controller in my 2002 Jeep Liberty. I've already installed the hitch but haven't got the wiring done yet. I want to do the brake controller as well but am confused. From what I've read if you don't have the overhead console and/or a factory tow package then you have to install a second harness for the brake controller. My Jeep didn't have a hitch before I put it on, but I did find the "electric brake" wire under the drivers kick panel. The issue I have now though (or at least I think I have) is that the behind the rear panel there is no blue wire. Under the hood fuse panel there is a tow fuse in place. Any ideas or more accurate info? Thanks.

 

[Cherrie]

That's a little weird, the blue wire usually is only there because it has the wire harness.
Sorry no help

 

[TheSauce05]

Yeah. I'm at a loss. Unless I'm looking in the wrong place in the back for that blue wire. Where does it run from the front? Maybe I can trace it.

 

[JeepJeepster]

Blue wire is part of the factory harness behind the right rear panel in the cargo area. Its not labeled or anything, its just part of the harness. Its the only blue wire like it in the harness, I just cut it and extended it on out. I bought a kit from etrailer, not the mopar harness.

 

[TheSauce05]

Blue wire is part of the factory harness behind the right rear panel in the cargo area. Its not labeled or anything, its just part of the harness. Its the only blue wire like it in the harness, I just cut it and extended it on out. I bought a kit from etrailer, not the mopar harness.

I got that. I was just wondering why I see it up front but not in the harness. Does anyone know how that wire is routed from the front to the back? Maybe I can find out where its gone missing.

 

[TwoBobsKJ]

I got that. I was just wondering why I see it up front but not in the harness. Does anyone know how that wire is routed from the front to the back? Maybe I can find out where its gone missing.

Since you don't have an EVIC or the factory tow package, the supplemental harness you need to buy will have the blue wire in it running from the back to the front. That's why you need the supplemental.

With both Mopar harnesses you'll have the factory tow wiring package - though not the entire tow package unless you also get the HD cooling. But most don't need that.

Bob

 

[TheSauce05]

Since you don't have an EVIC or the factory tow package, the supplemental harness you need to buy will have the blue wire in it running from the back to the front. That's why you need the supplemental.

With both Mopar harnesses you'll have the factory tow wiring package - though not the entire tow package unless you also get the HD cooling. But most don't need that.

Bob

Right, but what about the blue wire marked "Electric Brake" that I already have? It has to go somewhere. Even if it just ends somewhere.

 

[TwoBobsKJ]

Right, but what about the blue wire marked "Electric Brake" that I already have? It has to go somewhere. Even if it just ends somewhere.

The blue wire you already have will go to the brake controller's wire corresponding to the application of the brakes. The blue wire that's part of the supplemental harness functions the same way; in some model years the blue wire you have behind the kick panel was installed in ALL Libertys as a way to streamline assembly of the vehicle; some Libertys didn't come with the wire pre-installed so Chrysler put it in the supplemental harness. But without the supplemental harness the relays for the brake and clearance lights, and the 12V power from the Jeep's battery, are not powered. So the blue wire (either the one installed behind the kick panel or the one in the supplemental harness) is connected to the brake controller and passes the signal from the controller and along to the 7-pin trailer harness on your hitch. And - Voila! - trailer brakes :happy160:

Bob

 

[Cardhu]

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

better liberty specific faq i've found.

 

[profdlp]

Thanks, Cardhu! I have searched the forums a few times but missed that one.

 

[TheSauce05]

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

better liberty specific faq i've found.

This was actually the first post I read in regards to the electric brake and tow wiring. That's how I found the electric brake wire under the drivers side kick panel. According to that post, because I don't have a tow package or an overhead console, that wire shouldn't be there, but it is. I found it. It was labeled "electric brake." One of the very first replies was the same question that I'm asking, but it never got answered. That electric brake wire has to go somewhere. Either it goes all the way to the back of the Jeep like it's supposed to and I'm not seeing it, or it's lost in a loom somewhere. I'll look in the harness again to see if I missed it.

 

[TheSauce05]

BTW, JeepJeepster, we live in the same county. I think we may have had a conversation on here before.

 

[TheSauce05]

The blue wire you already have will go to the brake controller's wire corresponding to the application of the brakes. The blue wire that's part of the supplemental harness functions the same way; in some model years the blue wire you have behind the kick panel was installed in ALL Libertys as a way to streamline assembly of the vehicle; some Libertys didn't come with the wire pre-installed so Chrysler put it in the supplemental harness. But without the supplemental harness the relays for the brake and clearance lights, and the 12V power from the Jeep's battery, are not powered. So the blue wire (either the one installed behind the kick panel or the one in the supplemental harness) is connected to the brake controller and passes the signal from the controller and along to the 7-pin trailer harness on your hitch. And - Voila! - trailer brakes :happy160:

Bob

I missed this post the first time around. I understand the supplementary harness along with the standard harness. Just don't understand why that wire would be there and not attached to anything. I'm having a hard time believing the wire just disappears somewhere. If I install the supplementary harness then I have a wire labeled "electric brake" under my dash that doesn't do anything. Not that it's a problem, but doesn't make much sense.

 

[TheSauce05]

Ok, went back out and looked. Blue wire is not in the rear harness. Went back up front and traced the wire into the loom under the carpet heading towards the rear. Going to the rear, the blue wire is not in the loom coming out of the carpet, so it is in limbo somewhere under the carpet between the front and the back. Maybe it comes out somewhere and is unconnected in a plug or something. I don't know. Weird, though.

 

[TwoBobsKJ]

Ok, went back out and looked. Blue wire is not in the rear harness. Went back up front and traced the wire into the loom under the carpet heading towards the rear. Going to the rear, the blue wire is not in the loom coming out of the carpet, so it is in limbo somewhere under the carpet between the front and the back. Maybe it comes out somewhere and is unconnected in a plug or something. I don't know. Weird, though.

Simplest thing to do is install the supplemental harness since you know the electric brake wire will go from front to back and all relays are powered. I didn't have the tow package or hitch but I've since added OEM hitch, 7-pin harness, HD cooling including the in-radiator trans cooler, and an EVIC. The point being, using all OEM components everything works just as though it came that way off the assembly line. Plus, installation was simple with no fabbing required.

Bob

 

[TheSauce05]

Simplest thing to do is install the supplemental harness since you know the electric brake wire will go from front to back and all relays are powered. I didn't have the tow package or hitch but I've since added OEM hitch, 7-pin harness, HD cooling including the in-radiator trans cooler, and an EVIC. The point being, using all OEM components everything works just as though it came that way off the assembly line. Plus, installation was simple with no fabbing required.

Bob

Yeah, that's probably what I'm going to end up doing. The jeep already has the in radiator trans cooler. Not planning on hauling anything too heavy or very far. Thanks to everyone for the help. Wasn't trying to be difficult, just trying to figure this thing out and hoping I wouldn't have to buy an extra harness. Oh well.

 

[JeepJeepster]

Makes no sense at all for the wire to be under the dash and not in the rear area. I have a thread around here somewhere with pics from when i installed mine, cant seem to find it though.

Yup, believe we did. Black kj, right? I keep an eye out for ya.

 

[TheSauce05]

Makes no sense at all for the wire to be under the dash and not in the rear area. I have a thread around here somewhere with pics from when i installed mine, cant seem to find it though.

Yup, believe we did. Black kj, right? I keep an eye out for ya.

Yeah, the ugly black one. With the dents and tore up spare tire cover. LOL. I'm slowly getting her looking pretty again. Runs like a top, though. Actually, I passed you today on my way home from work. Top of the hill at the intersection in front of the high school on 32. Recognized the Jeep from your avatar. I was driving my Ford. And I've looked over your thread several times. I think that's where I first learned about the "blue wire" and subsequently went searching for it.

 

[Silvertwinkie]

The one measurement people forget!

Hey Prof,
I can tell you that the Liberty has a substantial towing capacity.
I realised this the first time I pulled onto a multi-lane. Everybody started pulling out expecting to overtake me only to discover that within 400 yds they had to accellerate to keep up!
No, there's only one thing to consider with the Liberty and that's the length of the trailer. As you know, I'm into my Airstreams and I've towed a few.
You have to remember that the Libby is quite compact, with quite a short wheelbase for a 4x4. The longer the trailer, especially when you have a central axle, the more yaw, or tendence to swing from left to right on the hitch. The longer the wheelbase the more stable the whole platform.
As a rule, I wouldn't tow anything longer than 25ft and at the limits you're best to stick around 50mph.
Marc
Ps, don't forget to put a circuit breaker on that blue wire supply.