Towing Question - 4 pin harness vs. 7 pin harness - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 04-30-2013, 08:16 AM   #1
Member
 
Join Date: Apr 2013
Location: Ellicott City, MD
Posts: 19
Towing Question - 4 pin harness vs. 7 pin harness

I have a 2012 JKU with the tow pkg. Has a 4 pin wiring harness, but I need a 7 pin harness to tow a small teardrop trailer. Is it an easy fix to convert it, is there an adapter or do I need run additional wiring? Any help or advice is greatly appreciated.

rblair99 is offline   Quote Quick Reply
Old 04-30-2013, 08:36 AM   #2
Jeeper
 
Dr.Ew's Avatar
 
Join Date: Apr 2013
Posts: 106
Any car store or similar should carry an adapter. It is cheap and easy.

Dr.Ew is offline   Quote Quick Reply
Old 04-30-2013, 08:38 AM   #3
Jeeper
 
CharlesS's Avatar
 
Join Date: Dec 2012
Location: Carmel Mountain, CA
Posts: 194
While there may be adapter harnesses available to convert from 4 to 7 pin; the better solution would be to purchase one from an online site.
CharlesS is offline   Quote Quick Reply
Old 04-30-2013, 08:41 AM   #4
Jeeper
 
joeuncool's Avatar
 
Join Date: Sep 2012
Location: Colorado Springs
Posts: 413
7 pin connectors usually include a connection for trailer brakes. Does your trailer have brakes? If so, you will need to take your Jeep in to have a trailer brake controller installed and they will take care of the connector at the same time. Trailer brakes are a good thing. Saves a lot of wear on your Jeep so you should use them if it has them.
__________________
I drive a JKUR. Everywhere I look I see places I want to drive up, over, or through.
joeuncool is offline   Quote Quick Reply
Old 04-30-2013, 08:53 AM   #5
Jeeper
 
ahsumtoy's Avatar
 
Join Date: Apr 2013
Location: Northern Arizona
Posts: 538
Trailer Brakes

Most likely, your trailer doesn't have electric brakes. You said it is small so I am making that assumption. The trailer could have surge brakes and you would not need to purchase a brake controller. Many small trailers like boat trailers, etc. have surge brakes. You can pickup a converter at ACE Hardware, Lowes, or even U-Haul. They are under $10. They just plug into the 4 pin on your jeep.
Attached Thumbnails
Click image for larger version

Name:	73011_primary.jpg
Views:	312
Size:	64.7 KB
ID:	243163  
ahsumtoy is offline   Quote Quick Reply
Old 04-30-2013, 08:59 AM   #6
Member
 
Join Date: Apr 2013
Location: Ellicott City, MD
Posts: 19
Thanks for the quick info. The adapter will work for sure. The trailer does not have brakes. But it has a battery onboard that draws a charge off the car battery. So, I assume the 7 pin adapter would just run the lights, and not charge the battery, right? I would need to replace the harness with a 7 pin harness, rather than the adapter, to have that functionality, right?
rblair99 is offline   Quote Quick Reply
Old 04-30-2013, 09:02 AM   #7
Jeeper
 
Dusthol's Avatar
 
Join Date: Jan 2012
Location: Williston nd
Posts: 876
Correct. The adapter will not charge the battery. The pic showing the adapter is wrong. That's for the 7 pin to 4 from vehicle to trailer u need the other way. It should have the female part of the 7 pin.
Dusthol is offline   Quote Quick Reply
Old 04-30-2013, 09:02 AM   #8
Supporting Member

WF Supporting Member
 
vtjohn's Avatar
 
Join Date: Jun 2012
Location: roanoke va
Posts: 123
Quote:
Originally Posted by rblair99 View Post
Thanks for the quick info. The adapter will work for sure. The trailer does not have brakes. But it has a battery onboard that draws a charge off the car battery. So, I assume the 7 pin adapter would just run the lights, and not charge the battery, right? I would need to replace the harness with a 7 pin harness, rather than the adapter, to have that functionality, right?

You would need a charge wire installed along with the 7-way to have the ability to charge the trailer battery.
vtjohn is offline   Quote Quick Reply
Old 04-30-2013, 09:04 AM   #9
Supporting Member

WF Supporting Member
 
vtjohn's Avatar
 
Join Date: Jun 2012
Location: roanoke va
Posts: 123
To be clear, there are no adapters (legally anyway) that would go from a vehicles 4 way to a trailer 7 way. There are a multitude of adapters that go FROM a vehicle's 7 way to smaller trailer plugs.
vtjohn is offline   Quote Quick Reply
Old 04-30-2013, 09:04 AM   #10
Jeeper
 
Dusthol's Avatar
 
Join Date: Jan 2012
Location: Williston nd
Posts: 876
Correct. I always had to make mine.
Dusthol is offline   Quote Quick Reply
Old 04-30-2013, 09:12 AM   #11
Jeeper
 
ahsumtoy's Avatar
 
Join Date: Apr 2013
Location: Northern Arizona
Posts: 538
Quote:
Originally Posted by Dusthol View Post
Correct. The adapter will not charge the battery. The pic showing the adapter is wrong. That's for the 7 pin to 4 from vehicle to trailer u need the other way. It should have the female part of the 7 pin.
Oops, got you the wrong pic. Sorry about that.
ahsumtoy is offline   Quote Quick Reply
Old 04-30-2013, 10:25 AM   #12
Jeeper
 
RedSectorA's Avatar
 
Join Date: Sep 2012
Location: Alabama
Posts: 201
I had to upgrade my four pin to a seven pin for my boat trailer. I have hydraulic disc brakes on the trailer but the reverse lights activate a solenoid that prevents the brakes from locking when backing up.

I ordered the following kit from the dealer and had them install it.

Trailer Tow Wiring Harness - 82210214ab | Mopar

This harness actually runs all the way to the engine and plugs into the ECU. I'm not sure why this is needed but it does.
__________________
2013 JKU Rubicon Billet Metallic
2.5" Rock Krawler Max Travel - 35" BFG KM2's - 17" Fuel Revolvers - Poison Spyder Brawler Lite and Skid - Warn Zeon 10S - JW Speaker Headlights
RedSectorA is offline   Quote Quick Reply
Old 04-30-2013, 10:47 AM   #13
Jeeper
 
onetraveller's Avatar
 
Join Date: Sep 2012
Location: Alaska
Posts: 723
It only takes about an hour to install the Mopar 7 pin harness, which replaces the 4 pin harness. The harness does not plug into the ECU. If the dealer is telling you it did, or that he had to "flash" the computer he's making sh!t up. It does attach to the battery and there is a wire for the trailer brake controller that runs through the engine bay to under the driver's side dash.

Here are the installation instruction.

http://www.quadratec.com/Assets/Installation/75397.pdf

Mike
__________________
2013 JKU Sahara, Commando Green - 2.5" Franken Lift - Rancho 9000xl shocks - 275/70r18 Cooper ST Maxx in summer - 265/70r18 Bizzaks in winter

http://www.wranglerforum.com/f202/re...ho-627602.html
onetraveller is online now   Quote Quick Reply
Old 05-14-2014, 03:25 PM   #14
Newb
 
Join Date: Sep 2012
Posts: 8
Old thread I know but I have a question about this harness. I ran everything to the engine compartment and the heat tape on the harness lines up where it should be for protection but when the end with the fuse and red/white/blue wire come up, the white wire looks like it is going to be too short. My 2012 JKUR is different from the instructions with the battery layout. Instead of the + and - posts going from side to side they go front to back. The battery is also separated in a plastic tub which the wire have to go over to get to the battery. Anyone else have this and did the wire fit? I have to find a nut to secure the wire on the - post as mine doesn't have one but if it does manage to fit its going to be very tight.
jgjg76 is offline   Quote Quick Reply
Old 05-14-2014, 09:13 PM   #15
Jeeper
 
onetraveller's Avatar
 
Join Date: Sep 2012
Location: Alaska
Posts: 723
Your 12 has the same engine layout as my 13. The MOPAR harness fits fine.

Mike
__________________
2013 JKU Sahara, Commando Green - 2.5" Franken Lift - Rancho 9000xl shocks - 275/70r18 Cooper ST Maxx in summer - 265/70r18 Bizzaks in winter

http://www.wranglerforum.com/f202/re...ho-627602.html
onetraveller is online now   Quote Quick Reply
Old 05-15-2014, 11:27 AM   #16
Jeeper
 
Ricks Rubicon's Avatar
 
Join Date: Mar 2013
Posts: 160
I installed the MOPAR harness on my '13. It was clean, straight forward, and everything actually wound up where it was supposed to go (all of the wiring actually reached the intended location).
Ricks Rubicon is offline   Quote Quick Reply
Old 05-28-2014, 05:22 PM   #17
Newb
 
Join Date: Sep 2012
Posts: 8
The instructions I have had me run the wiring out from the left tail light, under the frame and back up. I routed it above the frame and it fit fine after.

I also hear we may need a flash to enable the battery charge cable and running lights through the harness? Any truth to this?
jgjg76 is offline   Quote Quick Reply
Old 05-28-2014, 05:40 PM   #18
Jeeper
 
Join Date: Oct 2013
Location: Seattle & Tucson
Posts: 67
Quote:
Originally Posted by jgjg76 View Post
The instructions I have had me run the wiring out from the left tail light, under the frame and back up. I routed it above the frame and it fit fine after.

I also hear we may need a flash to enable the battery charge cable and running lights through the harness? Any truth to this?
The only "flash" I've heard of is to program the vehicle's computer for trailer sway damping. That's if you did not originally have a tow package from the factory. My JK came with Max Tow, and has "Trailer Sway Dampening" listed on the Build Sheet - which I believe is turning on a setting in the vehicle's computer.
__________________
2014 Jeep Wrangler Unlimited Sahara Anvil, Auto, 3.73
augsburg is offline   Quote Quick Reply
Old 05-28-2014, 06:06 PM   #19
Newb
 
Join Date: Sep 2012
Posts: 8
Also just realized the harness doesn't connect to anything aside from the battery and rear tail light so there wouldn't be anything for the computer to touch.
jgjg76 is offline   Quote Quick Reply
Old 05-28-2014, 06:23 PM   #20
Newb
 
aupfeil's Avatar
 
Join Date: Mar 2013
Posts: 12
When ordering a jku can I specify 7 pin instead of 4 pin?
aupfeil is offline   Quote Quick Reply
Old 05-28-2014, 07:17 PM   #21
Jeeper
 
jeepers29's Avatar
 
Join Date: Feb 2011
Location: Georgetown, Texas
Posts: 2,660
Quote:
Originally Posted by vtjohn View Post
To be clear, there are no adapters (legally anyway) that would go from a vehicles 4 way to a trailer 7 way. There are a multitude of adapters that go FROM a vehicle's 7 way to smaller trailer plugs.
This isa not true. I just bought one from O'reileys. It is made by Hopkins. You can find them on line as well.

__________________
98 TJ 4i in currie with Currie bars front and rear
2014 JKUR AMP"D,Ace slider,BFG AT/KO's 33's
Ace Tire carrier/ rear bumper,LOD Mid width front bumper

I love my country. That's why I despise the government.
jeepers29 is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



logo carid shop wrangler parts carid fender flares custom wheels store avs deflectors at carid
» Rates
Get low rates on auto insurance in Canada!

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 04:06 PM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC