bing tracking image
  1. Custom Fit Vehicle Wiring
  2. Hopkins
  3. Custom Fit
  4. Trailer Hitch Wiring
  5. 4 Flat
  6. Powered Converter
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 # HM11140504
lowest price pledge
Our Price: $67.21
You Save: 37%
Custom Fit Vehicle Wiring

Will this fit?

To see if this custom-fit item will work for you please tell us what vehicle you'll use it with.

Orders above $99 qualify for Free Shipping
Shipping Weight: 1.22 lbs
Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Custom Fit HM11140504
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

Need help with installation?
Locate installers near me
Quickly and easily install a 4-way trailer connector on your vehicle with this custom harness. T-connector plugs directly into existing wiring. Powered converter reduces strain on wiring system. 1-833-496-1390 to order Hopkins custom fit vehicle wiring part number HM11140504 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.
  • All Info
  • Reviews (7)
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

Hopkins Custom Fit Vehicle Wiring - HM11140504

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • Powered 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. Powered converter reduces strain on wiring system.


  • 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
    • Locate connection points in rear cargo area
    • Plug in connector
    • Run hot lead to car battery
  • Includes a tail light converter to ensure that your vehicle's wiring matches that of your trailer
    • Powered module connects directly to battery to avoid overloading vehicle's electrical system
  • Protective connection terminals resist corrosion
  • Comes with dust cap for 4-way flat connector, cable ties, and terminal grease packet for electrical connections
  • 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 and passenger's side. You will have to remove the rear threshold and some interior lining to access this harness. Once you've plugged in the connector, run the red hot lead up to your car battery. Connect the included fuse holder, and then connect the fuse holder to the positive terminal on your battery.

Once installation is complete, the 4-way flat connector will be stowed in your trunk.

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.

Powered Tail Light Converter

A tail light converter is built into this T-connector. This converter is a battery-powered unit that bypasses the electrical routes that are used by a basic wiring harness. As a result, there is virtually no draw on your tail light circuits.

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.

11140504 Plug-in Simple Hopkins T-Connector with 4-Pole Trailer Connector

This Product Fits The Following Vehicles

California residents: click here

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

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for Hopkins Custom Fit Vehicle Wiring - Trailer Hitch Wiring - HM11140504 Review

Today we're going to take a look at the Hopkins Plug-In Simple Vehicle Wiring Harness with the four way flat trailer connector. Now this is a custom fit part. It is designed to fit the 1998 to 2003 Ford Crown Victoria. Now on a custom fit product I always like to recommend for you to go to our website, use our fit guide, put in your year model vehicle and it'll show you if this will work for your application. Now this harness will provide this four way flat trailer connector at the back of your vehicle to power your trailers signal lights. It is compatible with five pole, six pole, and seven pole adapters that we do sell separately on our website.

This does connect very quickly and easily. Basically you just locate your connection points in the rear cargo area. Plug in the connectors one on each side, ground your white wire and then run your power wire to the vehicles' battery. Now this harness does include this weather proof taillight converter to ensure that your vehicles' wiring will match that of your trailer. It is a powered module, it does connect directly to the battery to avoid overloading your vehicles' electrical system. They do use protective connection terminals on this harness to resist corrosion.

Comes with everything laid out here on the table. Comes with the dust cap for the four way flat connector that you can attach to your four way. You can leave it connected if you want, then when you're not plugged into your trailer, you can just put that over the terminals to protect them from any damage or from the elements. Comes with the extra length of wire to connect to your vehicles' battery, an in line fuse holder with the included fuse. It comes with a grounding screw, comes with some cable ties and comes with a packet of terminal grease or dielectric grease for your electrical connections and a nice set of detailed instructions. Few specs on this harness, the maximum amperage on the stop and turn light circuits is 3 amps each side and on the taillight circuit it's 6 amps total.

Basically when you go to install this, what you'll do is go again to the rear cargo area. I would recommend to start on the drivers side and you'll take the connectors here that have the yellow and the red wire in it and then you'll attach this to the connectors on the vehicle that'll match up. Then you'll take the other connectors that have the length of green wire, that's for the passenger side. You'll run this length of wire over to the passenger side and then connect this right behind the taillights on the passenger side. You'll have your white wire with your eyelet on it.

You connect that to a good clean ground is there's one nearby. If not they include this screw that you can make your own ground. Then what you want to do is, your converter right here you do want to attach this to a flat surface, so it doesn't bounce around. They do include some extra cable ties to do that. Then we'll let your last wire, which you'll want to do is this red wire with the butt connector on it, this is what'll connect to your vehicles' battery. They give you this length of wire to run up to your vehicles' battery. Connect one end of length of wire to that and run this up to the battery. You don't want to connect this directly to the battery, you want to go through this in line fuse holder, connect that to the other end. Then once that's connected, you have your eyelet here this will connect to your vehicles' battery. Then pop open your fuse holder, take your included 15 amp fuse, pop it right into the fuse holder just like that. Put your cap back on there and you should be all ready to go. Like I mentioned the terminal grease, you want to put on all your electrical connections that you make to help resist corrosion. But that should do it for the review on the Hopkins Plug-In Simple Vehicle Wiring Harness with the four way flat trailer connector.

Customer Reviews

Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - HM11140504

Average Customer Rating:  5.0 out of 5 stars   (7 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. Powered converter reduces strain on wiring system.


I have used this type of product from Hopkins many times I love it just plug and play it's worth the money.

1998 Ford Crown Victoria

When I decided to equip my 1998 Ford Crown Victoria for towing, the cost quoted by local towing and trailer shops were pretty outrageous. It was easy to mount the hitch, but I was skeptical about the wiring. I am not one for cutting and splicing into an existing harness, hoping the results functioned properly. The Hopkins custom harness made it so easy and it worked perfectly. Just plug and play!

The wiring harness has worked perfectly any time I had to hook up my trailer. The installation was easy and the harness is well designed. I would recommend this companies line of products to anyone.
Jim L - 03/27/2020

1999 Ford Crown Victoria

This kit installed easily. The only thing to be aware of is that you will need to run a wire from the trailer light wire harness to the battery. I was able to easily come out of the trunk drain hole, under the felt and run the wire through the frame using a fish tape. I haven't hooked a trailer up to it yet, so I honestly don't know if it works, but I wanted to give 5 stars for installation and customer service. Excellent customer service with these guys. No pics because i was able to hide everything completely.


Instillation was was easy as I watched my friend who owns his own auto shop. Having said that, I could see that the construction and layout of the harness is impressive. I have had no problems running the lights on my trailer. Highly recommend this product.


Great product

2003 Ford Crown Victoria

Great product. easy to wire in with excellent instructions from video. No problem after one year.


Man sakes alive theses people move got my much needed parts in less than 36 hrs happy as can be thank you so much. Lee watson


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

  • Trailer Wiring Harness for 2003 Ford Crown Victoria P71
    For your 2003 Ford Crown Victoria P71, which is the Police Interceptor model, you will need the Hopkins Universal Install Harness # 46255. This hardwire kit includes everything needed to install a 4-Way trailer connector on the vehicle. The Hopkins Plug-In Simple Wiring Harness # HM11140504 that you mentioned unfortunately will not work on Crown Victorias equipped with the Police Package. There is not a custom harness like this available for this particular model.
    view full answer...
  • Solution for 4-Way Wiring on 2001 Mercury Grand Marquis
    Although they may be similar, the Hopkins Plug-In Simple Vehicle Wiring Harness # HM11140504 only works with the 1998-2003 Ford Crown Victoria according to the manufacturer. In order to add a wiring harness to your 2001 Mercury Grand Marquis you will need to use the Upgraded Heavy Duty ModuLite Circuit Protected Vehicle Wiring Harness with Installation Kit # 119190KIT.
    view full answer...
  • Trailer Hitch Recommendation for 2001 Ford Crown Victoria for Towing 2,600 lb Boat Trailer
    There isn't a way we can recommend you reinforce a Class I hitch so that it's capacities increase. Only solution we have for your 2001 Ford Crown Victoria would be a higher capacity hitch. Ideally you'd go with a Class III like the Curt part # 13707 which has more than enough capacity, but a Class II like the Curt # C12130 also has enough capacity for your 2,600 lb boat as it has a 3,500 lb trailer capacity. For trailer wiring you'd then want the Hopkins kit part # HM11140504 which is...
    view full answer...
  • Recommendation for Towing a Motorcycle with a 2001 Ford Crown Victoria
    The Curt Trailer Hitch Receiver - Custom Fit - Class III - 2" # 13707 for your 2001 Ford Crown Victoria will not have the capacity you are seeking. It is only rated for 400 lbs tongue weight for this type of application so your bike and the carrier will far surpass its capacity. I recommend using a trailer along with this hitch to protect your bike as a carrier will not work with your vehicle. For your wiring, I recommend the Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole...
    view full answer...

Do you have a question about this Custom Fit Vehicle Wiring?

  • Why

    At we guarantee:
  • Highest quality custom fit vehicle wiring for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate custom fit vehicle wiring information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jeff D
Installed by:
Jeff D
Employee Alexander C
Written by:
Alexander C

At we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.

Product Experts Available Now!
Call 1-833-496-1390