bing tracking image
  1. Custom Fit Vehicle Wiring
  2. Hopkins
  3. Custom Fit
  4. Trailer Hitch Wiring
  5. 4 Flat
  6. 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 # 41165
Our Price: $36.78
You Save: 24%
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: 0.51 lbs
In Stock
Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector Custom Fit 41165
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

In Use/Installed

Customer Photos

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 - no cutting or splicing required. 1-800-940-8924 to order Hopkins custom fit vehicle wiring part number 41165 or order online at Free expert support on all Hopkins products. Great prices 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 (58)
  • Q & A (0)
  • Photos
  • Why etrailer?

Hopkins Custom Fit Vehicle Wiring - 41165

  • 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 point behind rear bumper
    • 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
  • 90-Day limited warranty


This custom-fit T-connector plugs into your vehicle's wiring harness, which is located behind your rear bumper, near the driver's-side frame rail.

Once installation is complete, the 4-way 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.

41165 Plug-in Simple Hopkins T-Connector with 4-Pole Trailer Connector

Installation Details 41165 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 41165

Average Customer Rating:  4.8 out of 5 stars   (58 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.


Fantastic product. Truly plug and play. A 3 minute installation.


Works like it's supposed to good value name brand and best of all I received it Super fast Thanks etrailer Jimmie


Plug and play!! Doesn’t get any better than that!!!
Easy to order from the website
Fast delivery!!!


Plugged into existing wiring as directions stated. It's 3 minute job.

worked fine no issues but sold truck
greg j - 04/20/2022

2005 Chevrolet Colorado

This was the exact harness that I needed. My old one burnt up, so I needed a new one and this was exactly what I needed and wasn't too expensive.


Wiring harness worked as advertised and was extremely easy to install.

It’s all good!
RDHupp - 10/08/2021

2010 Chevrolet Colorado

This was installed on a 2010 Colorado pickup, extended cab work model. This was the 4 way flat that installed easily when pulling the factory wiring apart and installing the adapter. I also used this to use in conjunction with the 7 way with a 4 way flat and a trailer brake.

Everything is good. Thanks for asking.
Paul f - 07/17/2018

2011 GMC Canyon

Looks great! Fits like a glove on my 2011 GMC Canyon SLE crew cab! Easy to install with two people laying on our backs in a driveway. No jacking / lift is needed.

Took about 30 mins.

2006 Chevrolet Colorado

I received my wiring harness as sheduled. Installed it in 5 min. Ops checked it , everything was good. I have trailer lights again.
Thank you

Still working very good.
Brian J - 06/05/2019

2005 Chevrolet Colorado

The harness was an exact fit. Easy plug in. It has been problem free for over a year. Because I live in snow and heavy salt as a precaution I unplugged it last fall and used extra amount of waterproof dielectric grease on the connectors. Working good with no corrosion or light issues.

2006 Chevrolet Colorado

This wiring harness made it possible to connect my truck to my trailer with a professional and neat connection, which is less likely to be damaged in use. Once I found the proper plugs on my truck, the installation was quick and easy. I also used a knockout adapter in an existing hole in my rear bumper, so there is no loose wire hanging anywhere. The product works as advertised, no better or worse than expected.


Great product, plug and play into factory harness! Done!

Darren - 08/07/2020

2010 Chevrolet Colorado

I ordered the Hopkins Plug-n-Tow Wiring Harness from, specifically item 41165 for my 2004 Chevy Colorado. The instructions were spot on, I had the thing installed and tested in under 10 minutes. This product, from the over the phone support prior to ordering thru installation, exceeded my expectations.


Trailer wiring harnessI searched all over town for a wiring harness to hook up the lights on a trailer to my GMC pickup and couldn't find one anywhere. One store said they could order it for $49.00. I searched the internet and found etrailer in just a few minutes. About 10 minutes later I had found the part and ordered it using my credit card. It arrived at my house a few days later. I am very pleased with the product and service.

2005 Chevrolet Colorado

The Plug-N-Tow Harness worked perfect on my 2005 Chevy Colorado. Took about 1 minute to do the install.
The customer service at is top notch too. I placed my order a bit later that I probably should have so I ordered it 2 day delivery. I called their customer service just to make sure that it would get out on a truck that day. It not only got on the truck but I received updates from UPS and a personal email from etrailer rep that my order had shipped. Keep up the great customer service!


The service from was excellent. We were walked through the steps of the transaction in a professional manner. The mechanic for whom we acquired your product state that it worked well. I am confident that we will purchase from your company in the future.


Works as advertised

Chevrolet Colorado

Took me less than 5 minutes to install. The package even came with terminal grease. So far, it has worked flawless. I would recommend this product if you are using it for Chevy Colorado. I looked all over town trying to find this. And found it in no time. Easiest installation for trailer lights.

2008 GMC Canyon

The instructions for installation is very poor. Does not talk about ground wire and no views of connection and ties location.

2008 Chevrolet Colorado

Product and Service was excellent. Everything needed to install this hitch was included with the exception of some basic tools. Installation instructions pretty good as well.


Took just a matter of minutes to install very pleased with the purchase and will do business in the future if needed with etrailer.


What a great experience. Etrailer is a great company that knows what customer service means. Thank you for the quick delivery and the install video made installation a breeze.

2009 Chevrolet Colorado

Very simple installation. Watched a couple of videos on You Tube and had it done in a few minutes.


perfect fit and a quality product, best prices. I always come back to etrailer for more of their quality products.


This tail light converter was an exact replacement for the OEM part and worked perfectly.

Show More Reviews

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

  • Troubleshooting Vehicle Wiring Harness # 41165 Installation on a 2006 Chevrolet Colorado
    To isolate where the problem is occurring, I recommend testing the 4-Way plug on the # 41165 wiring harness with a circuit tester, without the trailer connected. Have someone assist you by engaging the tail lights, pressing the brake pedal, and flipping on the turn signals as you test each corresponding port on the plug. You should only see a flashing current on the yellow (left turn) and green (right turn) ports when the turn signals are activated. If the functions are reading correctly...
    view full answer...
  • Troubleshooting Malfuntioning Lights on Trailer Towed by 1999 Chevy Silverado
    I am assuming you are speaking of the trailer lights here. Since the trailer works fine when tested on a different vehicle, you have effectively eliminated the trailer as being the problem. Take a look at the trailer connector on your Silverado. Make sure it is not damaged or corroded. If you can see any green corrosion on the pins or sockets on the connector, it might be preventing the signal from getting through to the trailer. If the connector looks fine, use a circuit tester on the...
    view full answer...
  • Does Plug-N-Tow TM Vehicle Wiring Harness, # 41165, Stay Connected to a 2004 Chevy Colorado
    When the Plug-N-Tow TM Vehicle Wiring Harness, # 41165, is installed on your 2004 Chevy Colorado, you can leave it installed. It does not have to be removed if you are not towing. Just make sure that the small cover for the 4-Way connector portion is covering the pins so that it can protect it from dirt and corrosion. If you plan on only infrequent towing and find that the connection location for the wiring harness is easily accessible for you, you can disconnect the harness it you wanted....
    view full answer...
  • Does the Hopkins Plug-In Simple Wiring Harness for a 2005 Chevy Colorado Require a Ground Wire
    The Hopkins Plug-In Simple Vehicle Wiring Harness part # 41165 which is a fit for a 2005 Chevrolet Colorado does have a ground but it does not require any sort of separate ground connection. The Hopkins Plug-In Simple Vehicle Wiring Harness plugs in-line with a factory harness that is already grounded therefore an additional ground is not needed.
    view full answer...
  • Does Hopkins 4-Way Kit for 2004 Chevy Colorado have Amperage for LED Light Bar
    Yes, the Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 41165 would easily have enough amperage to power an LED tailgate light bar and LED trailer lights.
    view full answer...
  • Troubleshooting Dim Turn Signal and No Turn Signal with Running Lights On Trailer
    What you are describing sounds like you have a bad or weak ground on the trailer. Any time you see dim lights or certain functions not working when others are turned on (like with your left turn signal when the running lights are on) this usually means a weak ground connection isn't allowing for enough power to travel back to the assemblies. I first recommend checking the trailer's main harness ground to make sure it is securely attached to a clean bare metal surface that's free of any...
    view full answer...
  • Where to Connect the Hopkins Custom Fit Vehicle Wiring Plugs on a 2008 Chevy Colorado
    There are two places the Hopkins Custom Fit Vehicle Wiring, # 41165, will plug into your 2008 Chevy Colorado. Usually, you will find the trucks taillight harness under the truck, behind the rear bumper, near the drivers side frame rail. The Hoppy, has one male plug and one female plug. After unplugging the vehicles harness from the location mentioned above, you will plug the corresponding plugs on the Hoppy in line with the vehicles harness. You then mount the 4-pole at the rear of the...
    view full answer...
  • What is the Correct Trailer Wiring Harness for a 2007 Chevy Colorado
    Either wiring harness for the 2007 Chevy Colorado, # 118301 or # 41165, will work fine on the truck. They are different because they are made by different companies. The converter in # 118301 requires a separate ground whereas the other harness # 41165 does not and just uses the ground in the vehicle wiring where it connects. The harness you have will work just fine for you.
    view full answer...
  • Trailer Wiring Harness for 2008 Chevy Colorado that Keeps Truck and Trailer Turn Signals in Unison
    Usually a tow vehicle signal flash and a trailer signal flash are just about in unison so having them that far off is strange. If it were me I would use the Tekonsha harness # 118301 for the 2008 Chevy Colorado. It is very highly rated by customers and we also hear about fewer issues with the Tekonsha brand compared to other brands. I have linked a video showing how it installs but it installs the same way as the one you have.
    view full answer...
  • Troubleshooting Hoppy Plug-n-Tow Harness with no Right Turn Signals on a 2006 Chevy Colorado
    The best way to determine if the converter is damaged is to check the wires right at the box. Using a circuit tester, like part # PTW2993, probe the green wire just ahead of the box. If it does not have power, then the wiring may have come loose in the connectors or inside the taped wires. If it does have power, check the green wire on the other side of the converter. If this one does not have power, then the converter could be bad.
    view full answer...
  • Installation of Flat Towing Wiring Harness HM56109 in 2011 GMC Canyon
    Hopkins Plug-N-Tow (R) Vehicle Wiring Harness # 41165 includes a converter module that processes the lighting signals from your 2011 GMC Canyon before sending them on to your trailer. This module will be damaged if fed lighting signals from a motorhome. Before you flat tow the Canyon unplug the trailer harness # 41165 and plug in the Flat Towing harness # HM56109. You will also want to check your GMC owner's manual for any instructions regarding preparing the vehicle for flat towing....
    view full answer...
  • Left Turn Signal Not Working on 1999 Chevrolet Silverado 1500 Trailer Wiring
    If your 1999 Chevrolet Silverado has the factory trailer wiring, then I would suspect a blown fuse. The fuse would be located in the under-hood fuse box close to the fender. The legend on the fuse box lid will read TRL left turn and it is a 10-amp fuse. If your truck is using an aftermarket trailer wiring harness, then I recommend inspecting the connections for the harness. The harness should have a converter box between the trailer connector and where the harness splices into the vehicles...
    view full answer...
  • Recommended Trailer Wiring Harness For A 2005 Chevrolet Colorado
    When it comes to installing a trailer wiring harness on your 2005 Chevrolet Colorado The Hopkins Plug-In Simple Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 41165 is confirmed to fit your vehicle. This custom harness plugs into your vehicle's wiring harness, which is located behind your rear bumper, near the driver's-side frame rail. There is no ground wire that you will have to plug in using this harness. We do recommend using a small amount of grease on all electrical...
    view full answer...
  • 4-Pole Wiring Harness Installation for 2005 Chevrolet Colorado
    Since wire colors used for any given vehicle function can change between production runs, testing with a circuit tester like # PTW2993 is the best method to confirm what any particular wire does. If you want a simple 4-pole harness installation then a custom-fit harness like # 118301, # 41165 or # C55510 is the way to go. These require no testing, cutting or splicing of the truck's wiring, just plugging in the connectors and attaching the ground wire to a clean bare metal surface. Please...
    view full answer...

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

  • Why

    At we guarantee:
  • 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 Mike L
Expert Research:
Mike L
Employee Robert G
Expert Research:
Robert G
Employee Patrick B
Expert Research:
Patrick B
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Zack K
Video Edited:
Zack K
Employee Joshua S
Video Edited:
Joshua S
Employee Laura H
Updated by:
Laura H
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C
Employee Cole B
Installed by:
Cole B
Employee Brent H
Test Fit:
Brent H

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 1-800-940-8924