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Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Item # 42475
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Custom Fit Vehicle Wiring

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Hopkins Custom Fit Custom Fit Vehicle Wiring - 42475
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Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring - no cutting or splicing required. 1-800-940-8924 to order Hopkins custom fit vehicle wiring part number 42475 or order online at Free expert support on all Hopkins products. Guaranteed Lowest Price and Fastest Shipping for Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (82)
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Hopkins Custom Fit Vehicle Wiring - 42475

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • Converter
  • Hopkins

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring - no cutting or splicing required.


  • Provides a 4-way flat trailer connector at the back of your vehicle to power your trailer's signal lights
    • Compatible with 5-pole, 6-pole and 7-pole adapters (sold separately)
  • Connects quickly and easily - no cutting or splicing
    • Locate connection points in rear cargo area
    • Plug in connector
  • Includes a tail light converter to ensure that your vehicle's wiring matches that of your trailer
  • Protective connection terminals resist corrosion
  • Comes with dust cap for 4-way flat connector, cable ties, and terminal grease packet for electrical connections


  • Maximum amperage:
    • Turn lights: 2 amps per circuit
  • 90-Day limited warranty


This custom-fit T-connector plugs into your vehicle's wiring harness, which is located in your rear cargo area on the driver's side. You will have to remove the cargo strap and some interior paneling to access this harness.

Once installation is complete, the 4-way flat connector will be stowed beneath your vehicle, near the trailer hitch. A mounting bracket (sold separately) is recommended to keep the connector secure.

It is recommended that you use a small amount of grease on all electrical connections - the plugs on your automobile and the 4-pole connector itself - to help prevent corrosion.

Tail Light Converter

A tail light converter is built into this T-connector. Because most trailers run on a two-wire system - wherein the brake and turn signals are carried on one wire - the separate brake and turn signals from your vehicle's three-wire system need to be combined so they are compatible with the wiring system of the trailer. This converter combines the brake and turn signal functions of your automobile so that they run on one wire to properly activate your trailer's tail lights. Note: This will not affect how the tail lights on your vehicle operate.

42475 Plug-in Simple Hopkins T-Connector with 4-Pole Trailer Connector

Installation Details 42475 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Reviews

Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 42475

Average Customer Rating:  4.8 out of 5 stars   (82 Customer Reviews)

Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring - no cutting or splicing required.

2004 Jeep Liberty

Simple Installation, No modifications needed. Note: On the Jeep Liberty the floor plug for the wire run is above the tailpipe. Secure the wiring far away from the tailpipe.

2002 Jeep Liberty

The kit fit our Jeep perfectly. The instructions were clear as to how to install the part. One improvement that could be made is to mention that the connector has a tab that must be pressed to separate them. It took a while to figure that out.

2002 Jeep Liberty

I ordered this kit for my 2002 Jeep Liberty. Unfortunately it's the wrong kit. I would like to return it. The kit I need is Curt C55382 That I would like to order from you. Thank You

For the 2002 Jeep Liberty without a tow package you would want the Curt harness that you mentioned part # C55382
Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
. The Hopkins harness part # 42475
Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
is for the Jeep that has the tow package.
-- Etrailer Expert Jenny N - 05/02/2022


Easy to install and is durable.

2007 Jeep Liberty

Pretty straight forward installation on my 07 Liberty. The hardest part was getting to the right plug in, as on my vehicle there was little slack wire, but it wasn't brain surgery.
Follow the directions, which were pretty good, and you'll be wired up in half an hour, and 25 minutes of that time is removing the plastic trim panels and re-installing them. Next vehicle I need to set up for trailering, I'll be checking etrailer first to see if a ready to go system is available.
2 months of frustration in trying to wire it stopped right here!


Installation was perfect and a breeze. It’s been over a year of use and no issues at all. I will definitely contact trailer for any future wiring needs


Very easy to set up and start towing. Much happier that I decided to buy the kit rather than buying the trailer plug and trying to wire it into the vehicle wiring myself.

2006 Jeep Liberty

Purchased for 2006 Jeep Liberty. Installation was a snap. I pull my utility trailer alot and this unit has been trouble free. In the old days I would cut into my vehicle wire harness to add a trailer connection. Not anymore! This Hopkins adaptor is deffinetly the way to go.

The hopkins wiring kit was installed on our jeep liberty and has performed flawlessly since. I tow both a boat trailer and often pull a utility trailer, so it has been used quite a bit. And, it says alot about your company that you take time a year later to follow up with your customers!
John s - 04/10/2018


I am very happy with my purchase.


Recieved the hitch and writing promptly. Wiring was easy to install and works like a charm. Wish it came with some mounts for clamping it up as you pretty much have to depend on zip ties and all the vehicles structure. Took about 20-30 min to install and maybe an hour for non-mechanics.
Hitch took about half hour to install and works great. Very rugged. Was able to handle a small wreck while towing with no evidence of cracking.


This product works. We replaced the exact same brand/harness that we had previously installed years ago. It had quit working. We assume it was the wires at the plug that had broken as they are not protected. I would recommend buying the optional bracket to permanently install this on the hitch or at minimum use some electric tape and maybe plastic to protect the wires better.

But still a good harness. I used some dielectric grease on all connection points. It comes with a small packet. U may want to buy some extra.

2003 Jeep Liberty

The instructiosn did not match my car, there was no way to get to the plug from the inside, so I had to take off the whole inside panel off. The yellow slide switch on the plug did not release the plug lock, I figured out with a flat head screw driver stuck in-between releases the lock. Them to top it off, after everything was assembled, the trailer lights did not work!!!! I hope your customer service is up for a challenge.

Jeep Liberty

The service by E-Trailer staff is unsurpassed. I had several questions prior to purchase and they were all answered quickly and succinctly. Also my Jeep Liberty didn't "fit the description" of how to access the connection behind the passenger side rear panel; but they didn't pass it off, still tried to assist even though my vehicle was different (in case others run into this: my Liberty had no cargo bracket to remove; just take off the weatherstripping, and pry the panel off towards the center of cargo area). Job was very easy and had my wiring done in about 40 minutes. Longest part of job was being sure I kept wire away from exhaust, but it was no problem. I will definitely recommend and use E-Trailer again, Thanks

2003 Jeep Liberty

I installed Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Item # 42475 this morning and the harness went in without any problems and it functional checked as well. Sorry about not having pics, as I was in a hurry to get it done and forgot . I did find it easiest to pull the plastic panel behind the back seat on the passenger side out in order to access the plug for the tail lighting.

Jeep Liberty

The wiring harness was easy to install, and it worked perfectly fine. I am happy to be able to hitch the trailer to the Jeep Liberty.

2003 Jeep Liberty

Ordered the required wiring harness with converter for use with trailer hook up. It arrived when it was supposed to and installation was a snap. instruction were included which made the job even simpler. When I took the trailer for the required state inspection it passed with flying colors. So once again great job from 1AAuto on the timely shipping and the correct part. Thanks folks

2006 Jeep Liberty

After ordering this my shipping was upgraded and my part shipped out the next day. My part was securely packed within the shipping box with all parts included. Installation time on this was around 10 minutes, and made easier by the videos.
I would recommend these guys.


easy to install no problems

2007 Jeep Liberty

The wiring harness works fine and was easy to install. Good product. Thanks. Bill

2004 Jeep Liberty

Wow, not used to something being this easy! Pulling the plastic off the wheel well is the only pain and make sure you have a drill for the ground wire, left mine somewhere else. So I just bolted it to a hole in the wheel well instead with a spare bolt and lock nut.

2002 Jeep Liberty

The part worked perfect, the installation was done in 15 minutes. I like the fact that I can keep the plug connector inside the Jeep, in Michigan the road salt tears up trailer connections.

2006 Jeep Liberty

Simple and easy. Takes minutes.


Easy installation, almost... The ONLY criticism is I wish there was a video on how to take the pannel apart to get to the plug in... I found nothing on the internet... I work best with video presentations, along with alot of other people... Make a video and YOU WILL BE FAMOUS...


Didn't waste no time getting it out to me thanks


i have had to work on it twice to keep trailer lights working

Show More Reviews

See what our Experts say about this Hopkins Custom Fit Vehicle Wiring

  • How Do you Access the Factory Light Connector for Part 42475 on a 2002 Jeep Liberty
    If you look closely at Figure 1 of the instructions the hook should be to the right of the power port. You may have only a screw there. Remove the threshold panel first, Figure 2 part B. Then remove the screw and gently pull back the panel. The panel does run from the floor of the cargo area to the roof. Nothing should be separated. Just lift the panel up gently till you find the gray connector. It should be about 6 inches above the floor and 12 inches from the tail light.
    view full answer...
  • Where to Plug in Hopkins Vehicle Wiring Harness on 2007 Jeep Liberty
    You will plug the Hopkins Plug-In Simple Vehicle Wiring Harness # 42475 into your 2007 Jeep Liberty at the connectors which are behind the rear paneling on the passenger side. I have added a cut out which is from the linked directions that shows exactly where you will find the connectors. I have also added a link to a video review for you to check out of the Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 42475.
    view full answer...
    Image 1 for
  • Troubleshooting Hopkins Plug and Play 4-Pole Trailer Wiring Harness 42475 for 2003 Jeep Liberty
    A 4-pole wiring harness like Hopkins # 42475 combines the stop and turn light signals from the Liberty onto one wire for each side of the trailer. The green wire carries passenger side brake and turn signals and the yellow carries the same two signals for the driver side of the trailer. If you have a left brake light signal but you are finding that you do not have a left turn signal this could mean that one of the pins inside the vehicle or harness connectors is not making proper contact...
    view full answer...
  • Is A Separate Power Wire Needed When Installing Hopkins Wiring Harness # 42475 On 2003 Jeep Liberty
    The Hopkins Plug in Simple Vehicle Wiring Harness, part # 42475, is the wiring harness you will need for your 2003 Jeep Liberty. You are correct that the # 42475 wiring harness no longer requires a separate lead to the vehicles battery. I spoke with my contact at Hopkins and he said that the Jeep Liberty never really needed the separate power wire originally, but they decided to be on the safe side and to recommend it. They did further testing and found out that the Jeeps wiring harness...
    view full answer...
  • Missing Red Power Wire for Hopkins Wiring Harness # 42475 on 2006 Jeep Liberty
    The Hopkins Wiring Harness # 42475, does not require a wire be ran to the battery for a power source, this is why there is not a Red wire included in the packaging. In the original design of the wiring harness Hopkins recommended the separate power wire be ran to the battery. Later, Hopkins found that the Jeeps wiring harness supplies enough power for trailer lights, so the wiring harness was redesigned, and the separate power lead is not required or included. Hopkins has just not updated...
    view full answer...
  • Connection Point For a Hopkins Trailer Wiring Harness on a 2006 Jeep Liberty without Tow Package
    For a 2006 Jeep Liberty, the OEM plug is located behind the paneling in the back of the vehicle on the passenger side. There is a grommet located in the floor to allow for the 4-flat connector to be run down by the trailer hitch. I have included a link to the installation instructions for you.
    view full answer...
  • Fit of Hopkins # 42475 Trailer Wiring Harness on 2003 Jeep Liberty w/o Tow Package
    The Hopkins # 42475 Trailer Wiring Harness is compatible with all models of the 2003 Jeep Liberty, regardless of whether it has the tow package or not. I've confirmed this with my contact in the Tech services department at Hopkins.
    view full answer...
  • Does Hopkins Plug-In 4-way Connector 42475 For 2004 Jeep Liberty Require Additional Fuses?
    The Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 42475 you were looking at is confirmed to fit your 2004 Jeep Liberty Sport and will not require any additional fuses and does not require any upgrade to your blinker module. The # 42475 will plug into the existing factory connectors located behind the trim on the passenger side of the rear cargo area in your Jeep. Since the circuits are existing they are already fuse protected from the factory. I included...
    view full answer...
  • Recommended Wiring For Trailer When Tow Bar Wiring Is Present At Tail Lights
    For your 2007 Jeep Liberty, if you have a t-connector harness like the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118524 which connects behind the driver and passenger side tail lights as you mentioned you will not be able to connect the trailer and the tow bar wiring simultaneously. I've attached a video that shows how we run the wiring behind the rear bumper from side to side and how we run the power to the battery through the frame. You do have another option...
    view full answer...
  • Trailer Wiring Harness Options for a 2002 Jeep Liberty
    Oddly enough a tow package will not necessarily include a trailer hitch. Evey vehicle manufacturer has a different set of components that make up a towing package. The only definitive way to determine if your 2002 Jeep Liberty has a tow package is to have a dealer run the VIN number of the vehicle to tell you what options it has. f you find that your Liberty did not come with the tow package, then it will not be set up from the factory to accept the # 42475 harness. You will instead need...
    view full answer...
  • Routing a Power Wire for a Trailer Wiring Harness on a 2002 Jeep Liberty
    The only other trailer wiring harness available for a 2002 Jeep Liberty is # 42475 and it will only work if the vehicle came with a factory tow package. For all other models, you need to use the T-Connector harness, # 118524. Running a power wire to the battery is required because it provides the power to the trailer lights while at the same time protecting the wiring on the vehicle. The connection is required or the harness will not work. Routing the wire to the battery is not difficult...
    view full answer...
  • Wiring Harness Recommendation for a 2004 Jeep Liberty Without a Tow Package
    I verified with my contact at Hopkins that the Hopkins Plug-in Wiring Harness, # 42475, will work on your 2004 Jeep Liberty if it did not come with a tow package. He also stated that the factory connection is typically on the passenger side, but it may be possible that the manufacturer routed the connection to the driver side. I would recommend checking the passenger side for a connector before attempting to connect it to the connector on the driver side. One thing that you will want...
    view full answer...
  • How to Determine if a 2004 Jeep Liberty has a Tow Package to Pick Out Trailer Wiring
    The most efficient way to determine if your vehicle has the tow package is to take your VIN number to a Jeep dealer and have them run it. They will be able to tell whether or not you have the tow package with that information. Or you could check the wiring in your vehicle to see if the correct connectors are present on your vehicle. Check out the installation instructions I attached that will show you how to access the area. If you have the tow package, or if you find the harness then...
    view full answer...
  • 4-Way Trailer Connector for 2002 Jeep LIberty
    We do have 4-way trailer connectors you can install on your 2002 Jeep Liberty, with the correct one depending on if you have the factory tow package or not. If you do have the factory tow package on your 2002 Liberty, the correct 4-way harness is the Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 42475. If you do NOT have the factory tow package on your Jeep, the correct 4-way harness is the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector...
    view full answer...
  • Trailer Wiring Harness Recommendation for a 2005 Jeep Liberty
    If your 2005 Jeep Liberty has a factory tow package, you could use either the Hopkins harness, # 42475, or the Tow Ready harness, # 118381. The vehicles with a tow package have a factory connector made to add a wiring harness. Both products will perform equally as well. But if your Liberty did not come with a tow package, you will need to use Tow Ready Custom Fit Vehicle Wiring, # 118524. This is a circuit protected powered converter which is required to protect the sensitive electrical...
    view full answer...
  • Easy-Install 4-Pole Trailer Wiring Harness for Towing with 2004 Jeep Liberty
    Small utility trailers sometimes do not have lights and towing one of these naturally does not require the vehicle to have a trailer wiring harness, but larger trailers that are legally required to have lights will need the tow vehicle to have the appropriate type of wiring harness. Lighting requirements vary by trailer size and weight, and also by state; the linked article will help illustrate. It is easy to add a 4-pole wiring harness such as the USA-made Curt # C55382 that will provide...
    view full answer...
  • Hopkins Trailer Wiring Harness for a 2003 Jeep Liberty
    We do have a Hopkins trailer wiring harness that fits the 2003 Jeep Liberty but the part you looked at, part # HM42635, fit Wranglers from 2007 to 2014. Instead you need part # 42475 for your Liberty
    view full answer...
  • Difference Between Curt and Hopkins Trailer Wiring for a 2005 Jeep Liberty
    The biggest difference will be price. The two harnesses are basically the same harness made by two different companies. The Curt part # C55382 would be what I would go with over the Hopkins # 42475 because the price is better and because we seem to have better luck with Curt wiring than Hopkins. I attached an install video for this harness for you to check out as well.
    view full answer...
  • Recommended Wiring to Flat Tow A 2005 Jeep Liberty And Still Have 4-Way Trailer Wiring
    Since you want to flat tow your 2005 Jeep Liberty and you want to be able to tow with it, I recommend the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit # RM-15267. This will allow you to have a connection on the front of your Jeep for a motorhome wiring connection and will allow you to use diodes to protect and use your factory wiring. This wiring kit allows you to add a 4-way flat to the rear of the vehicle for towing your boat, using the Hopkins Plug-In Simple Vehicle Wiring...
    view full answer...
  • Comparison of Curt and Hopkins Wiring Harness for 2002 Jeep Liberty
    The Curt Wiring Harness # C55382 connects behind the tail lights of your 2002 Jeep Liberty. So you need a connector on each side to power the 4-pole. However, the Hopkins Harness # 42475 connects behind a panel in the rear compartment on the passenger side of your Jeep and doesn't connect on both sides. It's really just a matter of the harnesses plugging in at different places. They're both correct. The catch is that you'll need to make sure your Jeep has the connector behind the panel...
    view full answer...
  • Trailer Wiring Recommendation for a 2015 Ford Fusion Titanium
    The Curt Wiring Harness part # C56351 that you referenced has been confirmed as a fit for your 2015 Ford Fusion Titanium. The part number # 42475 that you also referenced is for Jeep vehicles and would not work.
    view full answer...
  • Recommended Trailer Wiring Harness For A 1995 Jeep Cherokee XJ
    Though we do have hardwire options available for your 1995 Jeep Cherokee XJ, there are no plug and play options currently available, unfortunately. If you decide to proceed with a hardwire kit, I highly recommend the Tekonsha # 119178KIT. This is a pretty quick and easy install and includes quick connectors, so no cutting will be needed. It's not plug and play, but it also isn't overly complicated either.
    view full answer...
  • Compatibility of T-1 Connector with Brake Controller on 2003 Jeep Liberty.
    The Brake Controller will be compatible with your T-1 Connector. You will need part # ETBC7, which is our Brake Controller Install Kit. The Kit comes with everything needed to install your brake controller, including a 7-way trailer connector adapter that will plug directly into your existing 4-pole trailer connector. If you have not yet decided on a brake controller, check out the Tekonsha Prodigy P2, part # 90885. The P2 is our best selling controller, primarily because it is so...
    view full answer...
  • Recommended Trailer Wiring Harness for a 2006 Jeep Liberty
    The trailer wiring harness I recommend for a 2006 Jeep Liberty is the Curt T-Connector Vehicle Wiring Harness part # C55382 because it offers plug-play installation. It provides all the of the required lighting functions for a trailer and you don't even have to worry about running a power wire. Please note, in order to mount the trailer connector outside the vehicle you'll also need the Mounting Bracket 4-Pole Flat part # 18144. The Hopkins Plug-In Simple Vehicle Wiring Harness part #...
    view full answer...

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