1. Wiring
  2. Curt
  3. Trailer Connectors
  4. Vehicle End Connector
  5. 4 Flat
  6. Plug and Lead
Curt 4-Pole Flat Vehicle Wiring Harness w/ Mounting Bracket

Curt 4-Pole Flat Vehicle Wiring Harness w/ Mounting Bracket

Item # C58345
lowest price pledge
Our Price: $14.16
You Save: 42%
Orders above $99 qualify for Free Shipping
Shipping Weight: 0.42 lbs
In Stock
zoom in 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


Wire your vehicle to tow a trailer with this universal, splice-in wiring kit. Includes 4-way flat connector, bonded wire, mounting bracket, and necessary hardware. Designed for use with 2-wire electrical systems. Lowest Prices for the best wiring from Curt. Curt 4-Pole Flat Vehicle Wiring Harness w/ Mounting Bracket part number C58345 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (12)
  • Q & A (7)
  • Videos (1)
  • Photos
  • Why etrailer?

Curt Wiring - C58345

  • Trailer Connectors
  • Vehicle End Connector
  • 4 Flat
  • Plug and Lead
  • Curt

Wire your vehicle to tow a trailer with this universal, splice-in wiring kit. Includes 4-way flat connector, bonded wire, mounting bracket, and necessary hardware. Designed for use with 2-wire electrical systems.


  • 4-Way flat trailer connector at the back of your vehicle powers your trailer's signal lights
    • Compatible with 5-pole, 6-pole, and 7-pole adapters (sold separately)
  • Rubber-molded connector and bonded wire provide maximum durability
  • Simple installation
    • Hardwires to existing wiring
    • Includes quick-splice connectors for easy splicing of wires
  • Electrical mounting bracket lets you attach connector to your vehicle


  • Wiring harness length: 60"
  • 1-Year limited warranty

58345 Curt 4-Way Flat Connector Socket Kit

California residents: click here

Video of Curt 4-Pole Flat Vehicle Wiring Harness w/ Mounting Bracket

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

Video Transcript for Curt Wiring - Trailer Connectors - C58345 Review

Speaker 1: Today, we're taking a look at the Curt 4-Pole Flat Vehicle Wiring Harness, with the included mounting bracket. This 4-way flat trailer connector can be used to add a new connector, or replace an older, damaged connector on your vehicle. It locates at the back of your vehicle to power your trailer's signal lights. It is compatible with 5-pole, 6-pole, and 7-pole adapters. Adapters are sold separately. This unit features a nice rubber molded connector, as well as bonded wire, to provide maximum durability.

It measures 60" long, and it's a simple installation. It hardwires to your existing wiring on the vehicle. It does come with quick splice connectors for easy splicing of the wires. Now, if you want to add more protection to the connection points, I recommend using heat-shrink butt connectors, which are sold separately, and available at etrailer.com.The unit also comes with your mounting hardware and the electrical mounting bracket. This lets you attach the connector to your vehicle.

That way, it's always accessible and easy to locate at the back of the vehicle, when you're ready to connect to your trailer. Now, this bracket has an overall width measurement, I measured from edge to edge, of 2-1/4" wide. Overall depth from front to back is 1-1/4" deep, and the overall height from bottom to top is about 1-3/4" tall. Those mount holes are separated on center by 1-11/16". When it comes to the wiring, you see it's a four wire design.

White wires are ground, yellow wires for the driver side turn and brake, green is for the passenger side turn and brake, and then the brown wire's for the taillights. That's going to do it for today's look at the Curt 4-Pole Flat Vehicle Wiring Harness with the included mounting bracket.

Customer Reviews

Curt 4-Pole Flat Vehicle Wiring Harness w/ Mounting Bracket - C58345

Average Customer Rating:  5.0 out of 5 stars   (12 Customer Reviews)

Wire your vehicle to tow a trailer with this universal, splice-in wiring kit. Includes 4-way flat connector, bonded wire, mounting bracket, and necessary hardware. Designed for use with 2-wire electrical systems.

- C58345

Seriously amazing product... I spent more time installing my trailer gate on the trailer than I did installing the wiring harness on my vehicle!! The instructions were clear, and installation was FLAWLESS!!! 811943

- C58345

Products were as listed - great quality and as always fast service! 796626

- C58345

great item, great price 716624

- C58345

As shown. 700298

- C58345

They always have what I’m looking for and delivery is always on time. 671139

- C58345

Bracket seems heavyweight good material 659386

- C58345

Exactly what I needed! 656890

- C58345

Item and Service was Great! Thank yo u. 650356

- C58345

Very quick shipping and items exactly as described. Thank You! 639610

- C58345

Perfect. I've never seen a trailer plug like this. It saves me from dragging my old plug on the ground occasionally 609446

- C58345

I was very happy with everything and would recommend this company to everyone 595879

- C58345

Great, prompt service. Would shop here again. 485570


Ask the Experts about this Curt Wiring

  • Recommended Trailer Connector for 2020 GMC Sierra 1500
    I'd recommend the # HM40975 which would provide both a 4-pole and a 7-way connector. This is what GM uses as the OEM trailer connector. The HM40975 would plug into the round US car connector that is plugged into the knockout next to the license plate. remove the knockout, unplug the socket from the rear of the knockout and plug the connector into the socket on the back of the # HM40975. The connector I recommended includes the mounting bracket and mounting screws, although your truck should...
    view full answer...
  • Length of Wire on Curt 4-Pole # C58345 Trailer Wiring Harness
    The wiring harness you mentioned, part # C58345 is 60 inches or 5 feet long. Rather than using the quick connectors provided with the kit I'd recommend soldering the connections and sealing the connection with heat shrink tubing like # DW05452. If you don't solder, we carry heat shrink butt connectors that are almost as good, part # DW05744-5
    view full answer...
  • 2019 Ford Ranger LED Tailgate Light Causes Trailer Light Out Error Code and Disables Backup Camera
    I have a solution for you but the T-One Vehicle Wiring Harness with 7-Way Trailer Connector # 22124 will not work since it connects to the same tow package port your existing factory 7 and 4-way connector plugs into. When you plug in a tailgate bar, like # BLS-1103 (or any accessory that uses lights) into your factory wiring, it tells your vehicle that there is a trailer connected, which is why it disables the backup camera lines, as you mentioned. Otherwise, the sensors would constantly...
    view full answer...
  • Available Vehicle and Trailer Wiring Connectors
    I cannot recommend custom-fit trailer wiring for your vehicles without knowing their year, make, model and version but I can help you with basic 4-pole type connectors for both the vehicle and trailer. I linked pages for both types of connectors. For a trailer side 4-pole you can wire in to your trailer we have items like # W787274 and # 54000-026. For a vehicle side 4-pole we have # 18252 and # C58345 which includes a bracket. For a bracket only use # 18144. I also linked a helpful...
    view full answer...
  • Can I Use Both The 7-Way and 4-Way At The Same Time?
    I have a solution for you, but you won't be able to use both the 7 way and 4 way plugs on the Hopkins # HM40975-11998 at the same time because the cover flaps do not allow for both to be open simultaneously. In order to plug both your 7 way and 4 way into the same plug you would need to use the Curt Trailer Connector Adapter # C57672 , which has the plugs side by side with dust caps that flip up to allow you to connect your plugs as desired. If you don't already have a wiring harness...
    view full answer...
  • How To Add a Trailer Hitch To a 5th Wheel Trailer to Pull a Boat Trailer
    The Adjustable Width Trailer Hitch Receiver part # C13703 is what I recommend installing on a fifth wheel trailer due to its universal nature that allows it to be installed on pretty much any trailer. The Adjustable Width Trailer Hitch Receiver provides a 3,500 lb gross trailer weight capacity which would be around the limit. In regards to installation, the process is pretty straight forward and you can use the included brackets as your template for drilling. In order to provide lights...
    view full answer...
  • Connecting Ignition Switched Power From 2015 Toyota Prius v to Enclosed Trailer
    You will need to use a circuit tester like # PTW2979 to find a wire in your 2015 Toyota Prius v that is hot only when you use your key (ignition switched power). When you do that you can simply wire in the Battery Isolation Solenoid # TR118665, which should be wired like in the accompanying diagram with 10 gauge wire # 10-1-1. I have added a link to a video review of the solenoid for you to check out.
    view full answer...

Do you have a question about this Wiring?

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality 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 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:

Expert Research:
Mike L
Edited by:
Lindsey S
Installed by:
Cole B
Written by:
Ronnie R
Updated by:
Kristina F
Updated by:
Matthew E
Updated by:
Isabelle B

At etrailer.com 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.