Quickly and easily install a 4-way trailer connector on your vehicle with this custom wiring harness. T-One connector plugs directly into existing wiring - no cutting, splicing or tapping required. Includes tail light converter. Call 800-298-8924 to order Tow Ready custom fit vehicle wiring part number 118335 or order online at etrailer.com. Free expert support on all Tow Ready products. Guaranteed Lowest Price and Fastest Shipping for T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector. Custom Fit Vehicle Wiring reviews from real customers.
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Custom Fit Vehicle Wiring > Trailer Hitch Wiring > Converter > 4 Flat > Custom Fit > Tow Ready

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

Tow Ready Custom Fit Vehicle Wiring

(12 reviews)

Code:   118335



Custom Fit Product

Shipping Special

Shipping Weight: 1 pounds


Tow Ready Custom Fit Vehicle Wiring - 118335

Quickly and easily install a 4-way trailer connector on your vehicle with this custom wiring harness. T-One connector plugs directly into existing wiring - no cutting, splicing or tapping required. Includes tail light converter.


  • 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 in rear cargo area
    • Plug in T-connector
  • Includes a tail light converter to ensure that your vehicle's wiring matches that of your trailer
  • Constructed of 16-gauge bonded wire
  • Comes with dust cap for 4-way flat connector


  • Maximum amperage:
    • Stop/turn lights: 2.1 amps per circuit
    • Tail lights: 4 amps per circuit
  • 1-Year limited warranty


This custom-fit T-One connector plugs into your vehicle's wiring harness, which is located behind the driver's-side and passenger's-side interior trim panels in your rear cargo area. These panels are near the rearmost doors of your van's cargo area.

Once installation is complete, the 4-way flat connector will be stowed in an out-of-the-way location within your cargo area.

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-One 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 your trailer. The tail light 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.

118335 Tow Ready T-1 T-Connector - 4 Wire

118335 Installation InstructionsInstallation Details 118335 Installation instructions

This Product Fits The Following Vehicles

1996 - 1999 Chevrolet Express Van Full Size

1996 - 1999 GMC Savana Van Full Size

1996 - 1999 Chevrolet Express Van without factory 4-flat or 7-Way connector

1996 - 1999 GMC Savana Van without factory 4-flat or 7-Way connector

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

Videos are provided As a guide only. Refer To manufacturer
installation instructions And specs For complete information.

Video Transcript for Trailer Wiring Harness Installation - 1997 GMC Savana

Alright. Today on this 1997 GMC Savana, were gonna install part number 18335 from Tow Ready.Now the foreign harness connects inside the van so we have to open up the doors and get to the wire harness on the inside. Now this is a cargo van so getting to the wire harness is really easy. Its all exposed. Ok, if this is a conversion van, we have to remove the interior panels to get access to this wire harness here as well on the other side. This is a wire harness right here.

Were gonna go ahead and disconnect. Just push in on this tab right here and you can pull it apart. This could be particularly stiff thats why I use a screw driver. Then well install the T-One harness in between, run the wires down then shoot it out here and out the lower hole. Well just leave that alone for now.

Now well take our other half of the T-connector, with the green wire, were gonna run it up and over to the other side to the same connection on the passenger side. Now, all we gotta do is take our extra green wire and zip tie it to the factory wire harness to take up the slack.Ok, at this point, you have an option with the wire harness with the 4-Pole. Now, you can leave it to the side and tuck it in the corner and when you need to use it, you just pull it out and shut the door on it. The door seal is soft enough so you wont smash the wires. Just make sure you stay away from the latch.

Or, also, we can run this out towards the bottom and out towards the outside. Okay, well take the wire harness and drop it down towards the bottom. To run it outside, were gonna go ahead and remove this panel, pull our wire out and put the panel back in place. Theres the wire harness. Well fold it over to the side just like this then put the cap back into place.

Now were gonna take our wire harness and run it over to the hitch. And from here, you can mount it anyway you want zip tie it to the hitch or use a specialty bracket.Alright, to mount our 4-Pole in this application, were gonna use part number 118149 from Tow Ready. So whats gonna happen is our wire is gonna fit between the prongs right here. And with the Tow Ready wire harness theres also a cutout for the cap as well. Lets take the two halves and, well snap them together and theres a couple of small screws to the holes to tighten it in place. And then if your 4-Pole is still loose inside, theres a set screw right here that you can tighten down, enough to make contact so it doesnt move. You dont have to crush it. Our mount uses zip ties to stay in place. Now you can mount this bracket anyway you like on the cross tube of your hitch. In this case, were gonna mount it like this. Well run our zip tie through and around the other side. Once youre satisfied with the placement of your bracket, go ahead and tighten down the zip ties.Alright, with that, that will finish for our install of part number 118335 and part number 118149 both from Tow Ready for 1997 GMC Savana van.

Customer Reviews

T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - 118335

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

Quickly and easily install a 4-way trailer connector on your vehicle with this custom wiring harness. T-One connector plugs directly into existing wiring - no cutting, splicing or tapping required. Includes tail light converter.

- 118335

by: chris m08/02/2013

looks great but this vehcile can never tow anything as the frame is rotted out at bolt points 92947


purchased new vechile same as old one installed reciever with ease and used all last summer no problems. great product

chris m - 01/31/2015


- 118335

by: Tracy T09/08/2013

I looked for a long time trying to find the right wiring harness for my van. This thing was awesome. It took me a total of about 20 minutes to hook it up and secure everything. This is by far the easiest way to hook up a trailer plug. Plus there are no wire splices to get wet.and corrode. The best part is everything I ordered showed up in 2 days.I would definitely order from here again. 98945

- 118335

by: Chris F.06/12/2013

Fantastic products, service and delivery time! I just re-wired my trailer, and 1999 Chevy Express Van with products and support from eTrailer.com. A video showing me the exact products I needed, as well as how to do it, made the job a simple one! Products arrived quicker than if I'd ordered them from a local trailer shop. Thanks. 84361

- 118335

by: GENE M.09/28/2011

Great Service, very easy to install-----Works Perfect. For the Price of Shipping, I would be out Money, Useing my Time and Gas looking for this Item. Thank You for your Excellent Service 24785

- 118335

by: kent10/28/2014

worked as specified, simple plug in installation. no cutting on existing vehicle wiring. kit contained everything needed to install the product. 158217

- 118335

by: David R05/26/2015

Super easy installation once interior panels are off - great quality and plugged in perfectly. 198059

- 118335

by: Ira J05/22/2012

Product was easy to install. Shipping was quick and on time. The video made iT easy To hook up. 41240

- 118335

by: Kevin F.08/31/2013

This kit makes wiring trailer lighting very convenient. I would recommend this to anyone. 97789

- 118335

by: Michael Polcaro01/06/2011

Fast Very happy! came fast. good product! Thanks! 5068

- 118335

by: JIM H.02/10/2011


- 118335

by: Jimmy04/04/2013

Great product. Very easy plug and go in stalation. 74086

- 118335

by: Hererman s02/21/2012

Harness fit like a glove very happy Herman 32141


Ask the Experts about this Tow Ready Custom Fit Vehicle Wiring
Do you have a question about this Custom Fit Vehicle Wiring?

  • Trailer Wiring Connector for 1999 Chevy Express Van
  • Attempting to wire a 4 pole like the # 18002 into the taillight system of your 1999 Express won't work, as you've found. The 1999 Express uses what is referred to as a separate or a 3 wire taillight system, where the running lights, turn signals and brake lights are carried on 3 different circuits. If your van had a 2 wire system, where the running lights were on one circuit and the turn signals and brake lamps were combined on the same circuit, the 18002 would've worked fine, but since...
    view full answer...

  • Installing a Brake Controller on a 1999 GMC Conversion Van
  • There are two possibilities. If your 1999 GMC Conversion Van has a tow package, there will be a port in which to plug in a wiring adapter from the Hopkins Agility Electric Brake Controller, # HM47294, to the port. It is part # HM47795. I have included a link to the installation details below. You would then need to install an Adapter 4 Pole to 7 Pole and 4 Pole, # 37185. But, if the van has a round plug with a cap inside the driver side frame rail instead of a bundle of wires in the jack...
    view full answer...

  • Where Does the Trailer Wiring Harness Install on a 1996 GMC Savana Van
  • You are correct. The Tow Ready wiring harness, # 118335, plugs in line with the tail light wiring and you will not have to splice into the wires at all. I have included a link to the installation details for you to view. Models that originally came with a 4-Way from the factory but need a replacement would use a different harness, # 118240. I have included a link to a video that shows how this harness installs.
    view full answer...

  • Installing 4-Pole Trailer Connector on 1992 GMC Safari
  • At one time, I believe there was a plug and play-type connector available, but due to the age of the vehicle and low demand, our suppliers no longer have them available. The lighting system of the first generation Safari is pretty simple. You can use our hardwire kit, part # 18252. Use the included circuit tester to find the correct functions behind the vehicle tail lights. Connect the white wire to a good ground, the brown wire to the tail light circuit, the yellow wire to the left...
    view full answer...

  • Recommendations for a 7-way on a 2007 GMC Savana Van
  • If your 2007 GMC Savana Van has a 7-way it should be either near the hitch underneath the rear of the vehicle or possibly if you open the rear doors it might be somewhere near the back, inside the vehicle. If your vehicle has the tow package it should have a 7-way. If you do not have the tow package you are going to need first a 4-way and then a 4-way to 7-way adapter. For a 4-way you would want a Tow Ready Custom Fit Vehicle Wiring # 118392. Check out the installation instructions...
    view full answer...

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

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Information for this part was:

Expert Research:
Michael L
Expert Research:
Michael H
Expert Research:
Jameson C
Video Edited:
Joshua S
Test Fit:
Nicholas E
Updated by:
Laura H

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Info for this part was:

Expert Research:
Michael L

Expert Research:
Michael H

Expert Research:
Jameson C

Video Edited:
Joshua S

Test Fit:
Nicholas E

Updated by:
Laura H

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