bing tracking image
  1. Trailer Wiring
  2. Hopkins
  3. Wiring Adapters
  4. Single-Function Adapter
  5. 4 Flat
  6. Plug and Lead
Hopkins 4-Pole Loop - 12" Long

Hopkins 4-Pole Loop - 12" Long

Item # HM48145
lowest price pledge
Our Price: $12.88
Trailer Wiring
Orders above $99 qualify for Free Shipping
Shipping Weight: 0.13 lbs
In Stock
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

Customer Photos


Need help with installation?
Locate installers near me
Extend your current 4-way connector by 12" with this 4-way flat wiring harness extension. Lowest Prices for the best trailer wiring from Hopkins. Hopkins 4-Pole Loop - 12" Long part number HM48145 can be ordered online at or call 1-800-940-8924 for expert service.
  • All Info
  • Reviews (82)
  • Q & A (0)
  • Videos (1)
  • Photos
  • Why etrailer?

Hopkins Trailer Wiring - HM48145

  • Wiring Adapters
  • Single-Function Adapter
  • 4 Flat
  • Plug and Lead
  • 0 - 5 Feet Long
  • 4 Flat
  • Hopkins

Extend your current 4-way connector by 12" with this 4-way flat wiring harness extension.


  • Trailer wiring extension loop extends your current 4-way connector
    • Extends wiring system by 12" for more flexibility
  • Includes car end and trailer end connections
  • Corrosion-resistant terminals ensure durability

48145 Hopkins 4-Way Flat Wiring Extension Loop - 12" Long

Installation Details HM48145 Installation instructions

California residents: click here

Video of Hopkins 4-Pole Loop - 12" Long

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

Video Transcript for Hopkins 4 Pole Loop Review

Today we're going to be taking a look at the Hopkins 4-Pole Loop 12-inch long 4 Flat Connector, part number HM48145. Here you can see our loop installed. This is going to be ideal if you want to create a quick-connect situation for anything on your vehicle where you have to separate it at times by simply unplugging it and plugging it back in when you're ready to go back on. You can also use this as an extension harness for a 4-Pole Flat if you should desire if your plug is just a little bit too short. It's all in a weather-tight seal, rubber housing. It's going to help keep out corrosion and moisture. This will work for up to a 4-wire system.

If you only need to use 3 as we did in this case, you can just leave the other one blank, should you ever need it in the future. Now let's go ahead and show you how to install it. We'll take it and we'll just cut it in half. Then we can separate out our wires. We're only going to be using 3 of the wires on it so we'll go ahead and cut these wires flat at the end. I'm going to strip back about 3/4 of an inch or so, so we can twist these and fold them over since they are a thinner wire.

I'm going to shorten these back a little bit more. We don't need so much length. We're going to strip back our white wire, about 1/4 of an inch on these. Then we'll do our brown. Then well just use the yellow one that we're going to tie into our red.

The other 2 colors are going to match up to what we happen to be using on this vehicle. Now we'll be taking our red butt connector. It's an 18-22 gauge by Deka available at our website, part number 05730-5. We'll place them on our wire, grip it. We'll just give them a tug, make sure they're on there nice and tight. Then we're going to match up our colors.

This could differ depending on what you're mounting it to, your vehicle. I'm going to take some electrical tape, wrap up our harness, cover up our butt connectors to help keep moisture and corrosion and dirt out of the inside of our connectors. We'll push that down. We can go to the bottom side of our vehicle and finish our wiring. We're going to strip these back about 1/4 of an inch. We're only using 3 of them. We did not use the green on the other side so we won't be using it on this side. Install our butt connectors onto our wires. Now that we have all of those on there snugly, we're going to take our red wire that we stripped back about a half an inch. We'll fold this one over. We're going to put that to the yellow that we ran on the other side that was attached to our red wire. Then we'll crimp that. Then we're going to tie into our brown wire here. That's going to be for our tail lights. We're just going to cut this one here coming out of this harness and strip it back. We'll take those 2 pieces of the brown wire that we stripped back, twist them together. We'll insert that into the brown wire from our plug, crimp it, give it a tug. Then we just need to tie into our ground wire, which is going to be right here. We'll do the same thing. We'll twist those together, we'll crimp that to the white wire from our plug. Now we're ready to plug in our wire to our quick-connect. Just match it up, snap it together, and we'll tie up all of our wires and clean up our install. Now we're going to take some electrical tape before we zip-tie everything up. We'll just cover up all of our butt connectors to help seal out any moisture or dirt that can get into our wiring and help prevent corrosion. Then we'll take some zip ties. We'll tie everything up and we'll trim off our excess. That's going to do it for our look at the Hopkins 4-Pole Loop 12-inch long Connector, part number HM48145.

Customer Reviews

Hopkins 4-Pole Loop - 12" Long - HM48145

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

Extend your current 4-way connector by 12" with this 4-way flat wiring harness extension.


I had purchased a Pro Series Cargo Carrier 63153 and the 20174 light kit. Assembly was very straight forward but I found that the 4-pole connector harness was too short. This 12" extension was perfect. Also, Jonathon at etrailer provided excellent customer support getting it to me while on a trip.


That's what I wanted and your service is prompt and courteous...


Product was exactly what I needed. It was a few days later than originally planned but no problem. I ordered a hitch cap but when I received it the electrical connection was just a bit short. This fixed the problem.


Great product... works as intended...
used to extend the factory hidden hitch 4 pin plug out from under the bumper.
Pic attached as used on my 2015 Dodge Charger SXT Rallye AWD with factory hitch.


Just what i needed




I've got a 2015 Ram 1500 that I had ordered a lighted hitch cover for ... The harness on the cover was too short ... I used this for an extension and it worked great ... I received it two days earlier than expected ... Ordering was easy ... Thanks ...


Great transaction, good product, and fast delivery as always.


The Hopkins 12" 4-flat connector extension and the Hopkins mounting bracket are top quality and will allow me to extend my truck's factory trailer wiring connector to the mounting bracket for a professional looking install. The mounting bracket will allow a much easier disconnect of trailer from truck.
The quick response from the etrailer Team is remarkable and I look forward to additional business with them.


Works as advertised. The only improvement that is needed is my plug adapter was a five pin, so there is an empty space when using my four pin extension to my trailer. I had to tape over this to avoid corrosion on the adapter plug. Maybe a "fix" could be made in the future with a "dummy" 5th pin to plug into the adapter?


Used to connect wiring to back of topper shell external led directional/brake lights on towed pickup. Acts as a quick disconnect if need to remove topper shell. works perfect.


Excellent quality. 12" is good if you just want to extend your harness to relieve any stress /stretching when turning corners or if you want to replace an existing damaged plug (solder and shrink wrap your repair).


The wiring harness was as good as advertised. Works great and was exactly what I needed.


Just want to say that etrailer has the best customer service people! Melissa worked with me to get me the correct part after I had ordered the wrong part, and shipped it to me complimentary. Both the new part and the wrong part were high quality and will solve my wiring problem. Thanks to etrailer for working with customers to make sure they get what they need!


Exactly what I needed to add a little more length to my trailer wiring.
I would also like to thank George and Carol at etrailer for their outstanding customer service and communication from the time I placed my order through the time I received my order. I have found it to be a real pleasure every time I have dealt with the kind folks at etrailer. These folks really know how to earn a customers repeat business.
Thank you,
Paul G


Very satisfied with the product. It was very well made and solved my problem of rewiring my auxiliary brake light that was trailer hitch mounted.


Not too much to say about just works! Made it possible to connect to the wire receptacle in the bumper step. Simple, cheap solution. Printed identification on individual wires is a nice touch. Seems like it would be fairly easy for the wires to separate from each other. But, a little electrical tape should take care of that, if needed. The connections fit well.


Works perfect to get a little extra length to trailer wiring harness.


Perfect for trailer wires that are just short of connecting to some vehicles. Great if you need a little more play in wiring for turns.


Cut it in half and used one end to splice onto a harness that I need an end on.


Bought this harness extension to tow brother-in-laws boat and it worked out great.


All items were received as described, packing was very protective and I ordered standard shipping but was upgraded free of charge. Great place for purchases for all your towing needs.


Wiring extension is well made. This extension will keep me from having to get on my hands and knees to hook up the lights. That's good for us old guys! Fast shipping and good communication. I will be a repeat customer.


It works great. I can keep the car's cover plate on and still connect my boat trailer.


This part exactly fits my requirements. Joseph was able to help me locate and determine this is the correct item I needed.

Show More Reviews

Ask the Experts about this Hopkins Trailer Wiring

Do you have a question about this Trailer Wiring?

  • Why

    At we guarantee:
  • Highest quality trailer 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 trailer 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 Jameson C
Expert Research:
Jameson C
Employee Joshua S
Video by:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Laura H
Written by:
Laura H
Employee Alexander C
Updated by:
Alexander C
Employee Andrew S
Installed by:
Andrew S

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.