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  1. Custom Fit Vehicle Wiring
  2. GMC
  3. Sierra
  4. 2003
  5. Tekonsha
FITS 2003 GMC Sierra
T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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

Retail:$50.54
Our Price: $34.94
You Save: 31%
Custom Fit Vehicle Wiring
Confirmed to Fit
2003 GMC Sierra

with factory 7-Way

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Tekonsha Custom Fit Vehicle Wiring - 118384
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Tekonsha custom fit vehicle wiring for your 2003 GMC Sierra are available from etrailer.com. Installation instructions and reviews for your GMC custom fit vehicle wiring. Expert service, and great custom fit vehicle wiring prices. etrailer.com carries a complete line of Tekonsha products. Order your T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part number 118384 online at etrailer.com or call 1-800-940-8924 for expert service.
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2003 GMC Sierra - T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

  • Custom Fit
  • 4 Flat
  • Trailer Hitch Wiring
  • Tekonsha
  • No Converter

Quickly and easily install a 4-way trailer connector on your GMC Sierra. This T-One typically plugs directly into the back of your factory-installed 7-way connector so you can retain the 7-way and also pull a trailer that has a 4-pole flat.


Features:

  • Provides a 4-way flat trailer connector at the back of your vehicle to power your trailer's signal lights
    • Retains functionality of factory-installed 7-way, RV-style connector (if present)
  • Connects quickly and easily - no cutting or splicing of wires
    • Locate connection points behind rear bumper
    • Plug in T-connector
  • Constructed of 16-gauge bonded wire
  • Comes with dust cap for 4-way flat connector


Specs:

  • Maximum amperage: 7.5 amps per circuit
  • 1-Year limited warranty


Installation

This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located behind the rear bumper. If you have a factory-installed 7-way, blade-style connector, the T-One will plug in between the 7-way and the OEM socket.


Once installation is complete, the 4-way flat 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.



118384 Tow Ready T-1 T-Connector - 4 Wire

Item # 118384

Installation Details 118384 Installation instructions

California residents: click here


Customer Satisfaction Score:


Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118384

Average Customer Rating:  4.8 out of 5 stars   (449 Customer Reviews)

Quickly and easily install a 4-way trailer connector on your vehicle. This T-One typically plugs directly into the back of your factory-installed 7-way connector so you can retain the 7-way and also pull a trailer that has a 4-pole flat.

by:

The adapter fit perfect was easy as 123 to hook up. I'm glad I didn't cut into wires to install the LED light bar. Unplug the 7 pin plug and plug in the adapter.



by:
2011 Chevrolet Silverado

I used this harness to add a tailgate strip light to my 3011 Silverado. The whole process including installing the light strip took 45 minutes. The harness plugged in in minutes and works beautifully.



by:
2013 GMCSierra

Have been looking for a T-connector for my trailer lights for two years. Truck has a seven pin connector built-in. Wanted my GMC emblem to light up when the breaks are applied. Was getting ready to cut and splice wires when I looked on the internet and learned about etrailer.com. Found the T-connector I needed. Took 5 days to arrive after ordering, and 5 minutes to install. Works great !



by:

Just what I needed .... perfect fit!!

Charlie N.

5/6/2024

Still working great ... use it everyday!



by:
2012 Toyota Tundra

I have a 2012 Toyota Tundra and I recently bought a pre-owned Leer camper shell. I used this harness to wire up the third brake light. I also used the brake light module. This setup worked perfectly and resulted in a neat and clean professional installation. Thanks etrailer, you had everything I needed for a successful prefect installation.

Ron G.

7/13/2023

I installed this unit on my truck one year ago. It was perfect then and it is still working perfectly without issue.



by:
GMCSierra

Perfect fit for 2022 Sierra GMC . This leaves your 4 pin vacant to plug in your boat trailer etc



by:

Slow start to a good impression but everything worked out.
1. It started with a delivery delay; I live two hours from the manufacturer but it took 3 weeks to get me my harness. When the error was found they over-nighted the harness to me.
2. The wiring in the harness was loose and would lose connection, disabling the lights. Pushing a connector back in to place, crimping it down and wrapping it in electrical tape solved that issue.
That was a month into owning the harness. It's been a year now and I've had no problems. I'm pleased with the compatibility and ease of which it took to install.

Don M.

5/11/2023

The harness has held up great. Needed no adjustments after original installation.



by:

Exactly as described, wires in nicely, has been working flawlessly since the installation!



by:
2016 Jeep Grand Cherokee

Purchased this hitch for my new 2016 Jeep Grand Cherokee Laredo online after being quoted a $700 installation price at my local Chrysler Dealership. After doing some online searching and reading multiple reviews I decided to give these folks a try. My husband and I watched a very detailed video explaining 3 different hitch options for my Jeep and quickly decided for the price it was worth giving it a try. From opening box to install was less than 20 minutes that included connecting trailer light kit that I purchased extra $$.$$. You can barely see it under my JEEP. I'm very pleased and can't hardly wait to use it. Thanks again etrailer.com you helped me prove my to my husband that it would work and saved me $600!



by:

Search hi and low to find what I needed or even for someone who even understood what I needed. I had no luck until I search on etrailer.com. They had exactly what I was looking for. Ordering was simple and delivery was quick. They even check in with me before durning and after shipping. I love this site. I'll definitely shop here first next time.



by:
2016 Jeep Grand Cherokee

I purchased a trailer hitch (C13182) and wiring adaptor (T-One 118384) for my 2016 Grand Cherokee. Received it within a few days and fit was perfect! Only took all of ten minutes to install with the help of my 5 year old. Thank You!



by:
2014 Jeep Grand Cherokee

Bought a trailer hitch, and wiring harness for my 2014 Jeep Grand Cherokee. etrailer was fantastic, right on the money with the videos and it was very helpful in choosing the right hitch. Very easy to install.



by:
2024 Ram 2500

Perfect fit.



by:

Website very easy to operate and fubd exactly the right part to fit my truck/trailer !!! Videos were very helpful even telling me what sockets and wrenches I needed to complete install by myself and Im a carpenter not really mechanically gifted. Will definitely use etrailer.com again without hesitation!!



by:

TRAILER WIRING HARNESS WENT TOGETHER REAL GOOD. IT ONLY TOOK A VERY LITTLE TIME TO INSTALL. THIS MADE INSTALLING MY LED BRAKE LIGHT KIT VERY EASY.



by:
2014 Jeep Grand Cherokee

Fit just like it should, engages securely and performs correctly. Nothing else I can ask for



by:

World class customer service



by:

great trailer hitch at fair price.



by:

Always worked for me when purchased in the past so I didn't expect anything less this time.

Reginald W.

8/20/2023

Ive had no problem with this item even thru a harsh winter use. Just make sure you use a little diox grease on the electrical pins so moisture doesnt ruin the contact

Etrailer Expert

Mike L.

9/13/2023

@ReginaldW Good advice, dielectric grease like # 11755 does a great job of keeping moisture out of your electrical connections.


by:

Excellent product and easy to install! Finished up the installation with products 118144 and 118140 for a clean looking install.



by:

Installed myself in about 30 minutes. 06 Silverado crew cab. Fit right up to factory fitting that was hidden up on top of the spare tire.



by:

Fit perfectly, and the [online] video was very helpful



by:

Works perfectly



by:
2017 Jeep Grand Cherokee

I recently purchased a new 2017 Jeep Grand Cherokee. However, the vehicle was not equipped with with a trailer hitch but came pre-wired for trailering. I asked if the dealership could install a hitch/wiring and was informed that they subcontract the work to a local trailer rental company. I went to the company and was told it would cost approximately $400 and I would have to leave my vehicle with them for four hours, which would have been very inconvenient because I live 50 miles away. As a result, I researched alternatives online to see if I could install the hitch and wiring myself. etrailer.com had the best customer reviews and help videos, so I placed an order for the hitch and wiring harness. My wife and I installed them yesterday, which took about an hour. I saved $270 from what the trailer company was going to charge me. Very happy with the purchase.

Gary G.

4/28/2018

Working fine.



by:

Easy to use web site - got the correct part - I have already ordered more parts - this time for my trailer!!! I will always choose etrailer for my parts

Frank

1/30/2023

It was so easy to install and I have not had any issues with it. Best add on I ever added!!!


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449
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