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  1. Tow Bar Wiring
  2. Tow Ready
  3. Diode Kit
  4. Splices into Vehicle Wiring
  5. Universal
  6. Tail Light Mount
Tow Ready Tail Light Isolating Diode System with 4-Pole Connector

Tow Ready Tail Light Isolating Diode System with 4-Pole Connector

Item # TR118821
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Retail:$119.18
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Tow Bar Wiring

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This combined diode system features a Y-harness that allows your RV to power the lights on your towed vehicle without the vehicle sending electrical feedback to the RV. The 2-diode system does the work of 4 and protects both electrical systems. Lowest Prices for the best tow bar wiring from Tow Ready. Tow Ready Tail Light Isolating Diode System with 4-Pole Connector part number TR118821 can be ordered online at etrailer.com or call 1-800-496-5010 for expert service.
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Tow Ready Tow Bar Wiring - TR118821

  • Diode Kit
  • Splices into Vehicle Wiring
  • Universal
  • Tail Light Mount
  • Tow Ready

This combined diode system features a Y-harness that allows your RV to power the lights on your towed vehicle without the vehicle sending electrical feedback to the RV. The 2-diode system does the work of 4 and protects both electrical systems.


Features:

  • Kit includes everything required to wire vehicles with a 2-wire system for towing behind a motor home
    • Y-Harness with 1 driver's-side and 1 passenger's-side diode
      • Each diode contains a tail light and combined turn and stop feed
    • 4-Pole flat connector extension
      • Runs along your tow bar
      • Connects RV wiring system to the Y-harness
    • 8 Wire connectors, 1 ring terminal and 4 zip-ties
  • System connects your RV turn signals, running lights and brake lights to your towed vehicle's lights
  • Mounting bracket for 4-way flat connector (18144) sold separately
  • 1-Year limited warranty


Tow Ready Tail Light Isolating Diode 2 wire to 2 wire diagram

Tow Ready Tail Light Isolating Diode 2 wire to 3 wire diagram

Please note for 3-wire system on towed vehicle: With this kit, the towed vehicle's brake lights will function as both the brake and turn lights. A wiring converter (118158; sold separately) and 2 additional diodes (also sold separately) will be needed if you want to retain separate turn and brake signals.



118821 Tow Ready Tail Light Isolating Diode System with 4-Pole Connector

Installation Details TR118821 Installation instructions

This Product Fits The Following Vehicles



California residents: click here



Customer Reviews

Tow Ready Tail Light Isolating Diode System with 4-Pole Connector - TR118821

Average Customer Rating:  4.8 out of 5 stars   (194 Customer Reviews)

This combined diode system features a Y-harness that allows your RV to power the lights on your towed vehicle without the vehicle sending electrical feedback to the RV. The 2-diode system does the work of 4 and protects both electrical systems.

by:

Instructions were helpful, I ran the wire through the inside of my Mini Cooper. Real easy, did not needed to lift the car. Works well




by:

As it took >8mos to get the tow hitch for to use this wiring with, I have only used it once. however, I will say that install was very easy with the video on your website and it did work flawlessly.




by:

I have yet to install the wiring harness but will do so in the next few weeks in preparation for a trip this summer. Inquire again next year and I will respond.


Comments
I installed and used the wiring harness last year from Florida to Massachusetts and back. It was easy to install and worked perfectly the whole trip.
Norman - 03/14/2022


by:

I have been using trailer for years. Never had a single issue with product or delivery!




by:

Works perfectly had no problems with installation doing it my self




by:
2019 Jeep Cherokee

Worked as advertised, good product with easy installation


Comments
Works great!
Denny - 07/20/2022


by:

I’m giving it 5 stars only for the fact that it works as described but instructions lack on its installation I had to go online and lookup the manufacturer on how to hook it up on tail lights..


Comments
Sorry for the installation trouble. Here is an installation video for a 2019 Jeep Cherokee:
-- Etrailer Expert Sierra K - 12/22/2021


by:
1997 Suzuki Sidekick

The tow ready tail light isolating diode system is what i need but the installation instructions does not apply to my vehicle. I have a 1997 Suzuki sidekick JX. The instructions says, remove the cover to compartment where jack is stored, to access the wiring harness and find plug. My jack is stored under the passenger front seat. No storage compartment in rear of vehicle. So far i haven't found the harness I'm suppose to unplug more later when and if i find it.




by:

Needed help from etrailer's tech support, as color code was different.
Tech support was great. Item works as intended!


Comments
Have towed thousands of miles with no problems!
Chuck - 01/27/2022


by:

Was able to travel a lot of states with the hook up, all worked as expected and I appreciate all the help Roger gave me. Will definitely purchase from etrailer in the future.




by:

The quality is top notch. Fits my car like Cinderella's slipper.




by:

This has worked perfectly. It was easy to install and is still working great after a year of use.


Comments
Wonderful! Still working perfectly.
Brittainy - 06/02/2022


by:

The system was easy to understand and install. Works as expected.




by:
2019 Ram 1500

Have not installed the wire
ing kit as
of yet




by:

very good parts.




by:

I used this product with Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector
Item # C56407 in order to prevent splicing into the vehicle wiring harness. It was more expensive but it created a plug and play solution for my gladiator Jeep. Follow the videos to a t and you cannot go wrong also follow the attached diagram if you are going use my trick or wire by splice. It will save you some trouble shooting time.




by:
2019 Dodge Ram Pickup

I am very pleased with the Demco setup. I'm towing my 2019 Ram 1500 behind 2017 Tiffin Phaeton bus. With the help of etrailer videos I was able to install the base plates, light wiring, brake system and battery charger completely by myself. It took some effort and a couple of days but save lots of money and know that it is done right.




by:

Fit perfectly. I like the new coating. Doesn’t flake off like the old one did.




by:

easy to install I am very happy with your product, the video you provided was a great help, I just moved the brake indicator LED to the Motorhome dash instead of the tow vehicle and I provided power to the controller from the motorhome.




by:

Followed directions and completed job in a little over 4 hours. had trouble reinserting some pins in difficult locations.

Later in the month I installed the wiring tow package. Goofed up and crossed a wire and it took me two days to get back under the truck and rewire. all is working great according to directions...…….

I will use etrailer again, good service, great service representatives...……..jt




by:

easy install worked perfectly.




by:

I replaced a previous version and found this one was easier to installed.




by:

Installing this kit was no small feat. It required disassembly of the rear bumper and taillight assemblies, as well as snaking the wiring - intelligently - all the way from the back to the front. However, once installed it's been performing admirably for over a year and 10k miles of towing.




by:

A little tricky to install due to jeeps wiring color codes , but with a good test light it was a piece of cake. Routing the wires to the front of the towed vehicle without a lift was not fun but was not that hard if you don’t mind lying on your back




by:
2019 Jeep Cherokee

Excellent quality. eTrailer's online installation video showing how to install this on my 2019 Cherokee was exactly what I needed. I would have hired this out along with the tow plates but I'm confident I can do it myself with eTrailer's online help.



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