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  1. Custom Fit Vehicle Wiring
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Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

Item # C55325
Our Price: $38.70
You Save: 40%
Custom Fit Vehicle Wiring

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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, splicing or tapping required. Converter is made using SMT to ensure superior performance. 1-800-940-8924 to order CURT custom fit vehicle wiring part number C55325 or order online at Free expert support on all CURT products. Great prices and Fastest Shipping for Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
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  • Reviews (18)
  • Q & A (0)
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  • Why etrailer?

CURT Custom Fit Vehicle Wiring - C55325

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

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, splicing or tapping required. Converter is made using SMT to ensure superior performance.


  • 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 of wires
    • Locate connection points behind rear bumper
    • Plug in T-connector
  • Includes a tail light converter to ensure that your vehicle's wiring matches that of your trailer
  • Constructed using surface-mount technology (SMT) for consistent, reliable performance
    • Maximizes trailer light yield and intensity while producing minimal heat
    • Ensures superior operation in rough road conditions
  • Comes with dust cap for 4-way flat connector


  • Maximum amperage:
    • Stop/turn lights: 3 amps per circuit
    • Tail lights: 5 amps per circuit
  • Limited 1-year warranty


This custom-fit T-connector plugs into your vehicle's wiring harness, which is located behind the rear bumper, along 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 with Surface-Mount Technology

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.

Curt builds each tail light converter using surface-mount technology (SMT). This method of construction involves soldering electronic components directly to the surface of a printed circuit board. SMT eliminates the need for leads, which are used in older through-hole technology. The result is a circuit board that is smaller yet provides more routing area and that offers superior performance, reliability and durability.

Curt SMT Circuit Boards

Circuit boards constructed using SMT have been shown to perform better under rough conditions with excessive vibration than those made using the through-hole method. And where would vibration be more likely to occur than in towing applications? Curt converters also produce less heat, leading to increased durability and longer life. In addition, lower levels of resistance ensure better performance, especially for parts that operate at higher frequencies.

Each Curt circuit board is made using high-quality components that are pieced together in the most technologically savvy fashion, leading to greater predictability and reliability in functioning.

55325 CURT T-Connector - Surface Mount Technology - 4 Wire

Installation Details C55325 Installation instructions

This Product Fits The Following Vehicles

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - C55325

Average Customer Rating:  4.9 out of 5 stars   (18 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, splicing or tapping required. Converter is made using SMT to ensure superior performance.


I have purchased a number of items from etrailer. They provide excellent service at a very fair price. First place I always look. This is a very nice hitch with a well applied durable finish. Easy to install.

1997 Ford Ranger

Arrived when expected - easy installati on.


easy hook up work first time Thanks

Ford Ranger

Converter is only convenient way to hook up trailer wiring to Ford Rangers and Mazda pickup's that have a separate circuit for the turn signals. The amperage ratings for the circuits supply adequate amperage for most trailer lighting and according to the documentation there is a circuit breaker for any overload situations built into the converter. Instillation couldn't be any simpler on the Ranger. This is a replacement for another brand converter that burnt out because the circuits didn’t have the capacity for the amperage draw on my new trailer.


Fit perfectly.


Very glad I purchased this product. Factory harness hookup vs. wire splice is the WAY TO GO.


replaced the one on my truck and it works great



1999 Ford Ranger

Fit perfectly and works great.
easy to install.


Great product and was shipped and here at my home very fast. Also the follow up from company employees was great. I will buy from this company again



Product is as expected and arrived in good condition on time


Works as expected & easy install just be sure to anchor brain box securely.


Easy to hook up. Solved the problem thanks

1996 Ford Ranger

Perfect fit, works great

1999 Ford Ranger

Works just like my old one. Great pric e.


1993 Ford Ranger


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

  • Trailer Wiring Harness Recommendation for a 1999 Ford Ranger
    Yes, the Curt Wiring Harness part # C55325 that you referenced would be the correct trailer wiring harness for your 1999 Ford Ranger that does not have the tow package wiring. I attached installation instructions for this harness for you to check out as well.
    view full answer...
  • 1996 Ford Ranger Trailer Wiring Harness Installation
    The Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C55325 is as you stated designed to fit your Ford Ranger, so it will handle getting wet from puddles and rain. What it is not designed for is submersion, so you will be fine with your mounting location. This system does not require the ring terminal for a ground to your truck frame. It will be adequately grounded as designed.
    view full answer...
  • 4-Way Trailer Wiring Harness Recommendation for 1999 Ford Ranger
    What you need is a 4-way trailer wiring harness for your 1999 Ford Ranger. The kit you want is the T-One part # 118325 which is a confirmed fit. It installs by plugging in line with the taillights of the truck. I attached an install video for this for you to check out as well.
    view full answer...
  • Troubleshooting Turn Signals Not Working On Trailer Pulled by 1999 Ford Ranger
    The Curt # C55325, is the correct wiring harness for your 1999 Ford Ranger, and it does have a converter. Your trucks turn signals are separate from the brake light circuit on your Ranger. There could also be a ground problem. The taillights ground through the mounting studs on the trailer. Check to see that there is no dirt or corrosion that could cause a bad ground. Next, check the ground at the trailer connector. If you find no ground problems, you will need to check the wiring all...
    view full answer...
  • Is There an Under-Dash Brake Controller Connection Port on the 2005 Mazda B3000 DS Pickup
    An under-dash quick-connect brake controller port is not offered by Mazda on their smaller pickups, so your brake controller will require a hard wire installation. You will use the # ETBC7 brake controller installation kit that you referenced. A video and article on installing this kit are included for you. If your truck has a 7-way already you can instead use kit # 5506. If your truck does not already have a 4-pole flat trailer connector at the rear bumper you will also need a wiring...
    view full answer...
  • Wiring Harness for 1994 Ford Ranger
    I can't tell you specifically how a wiring harness you purchased from a competitor will install. The harnesses we offer for a 1994 Ford Ranger, the T-One Vehicle Wiring Harness # 118325, Curt T-Connector # C55325 and Hopkins Plug-In Simple Vehicle Wiring Harness # 40215 are all extraordinarily easy plug-in connectors. What I can offer you are general guidelines on how to splice in a 4-flat. What you will need in order to do this are the Cordless Circuit Tester # PTW2979 as well as at least...
    view full answer...
  • Troubleshooting Trailer Wiring for Fleetwood Pop-Up Trailer and 2003 Mazda B3000 Pickup
    A potential cause for your issue is a weak ground connection. Trace the white ground wire from your 4-pole back to where it attaches to the vehicle frame. This ground must be secured to a clean and rust-free spot on the frame. If necessary sand off the rust/dirt from that grounding point and reattach the white ground wire or relocate it a new spot. If this does not correct the problem then I suggest you next test your existing 4-pole trailer connector on your Mazda to confirm it is functioning....
    view full answer...

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Info for this part was:

Employee Leah B
Edited by:
Leah B
Employee Lindsey S
Written by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Updated by:
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Employee Isabelle B
Updated by:
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