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  1. Custom Fit Vehicle Wiring
  2. Lexus
  3. 2008
  4. CURT
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 # C55563
Our Price: $53.15
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Custom Fit Vehicle Wiring

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The best technical support and full custom fit vehicle wiring installation instructions. Great price custom fit vehicle wiring and expert service. Lexus , 2008 custom fit vehicle wiring by CURT are available from For expert service call 1-800-940-8924 to order your Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector part number C55563, or order online at
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  • Reviews (55)
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CURT Custom Fit Vehicle Wiring - C55563

  • Custom Fit
  • Trailer Hitch Wiring
  • 4 Flat
  • Powered 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. Powered converter reduces strain on wiring system and 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
    • Locate connection points in rear cargo area
    • Plug in T-connector
    • Run hot lead to car battery
  • Includes a tail light converter to ensure that your vehicle's wiring matches that of your trailer
    • Powered module connects directly to battery to avoid overloading vehicle's electrical system
  • 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: 6 amps per circuit
  • Limited 1-year warranty


This custom-fit T-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. Once you've plugged in the T-connector, run the hot lead up to your car battery. Connect the lead to the included fuse holder, and then connect the fuse holder to the positive terminal on your battery.

Once installation is complete, the 4-way 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.

Powered Tail Light Converter with Surface-Mount Technology

A tail light converter is built into this T-connector. This converter is a circuit-protected, battery-powered unit that bypasses the electrical routes that are used by a basic wiring harness. As a result, there is virtually no draw on your tail light circuits.

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.

55563 CURT T-Connector - Surface Mount Technology - 4 Wire

Installation Details C55563 Installation instructions

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector - C55563

Average Customer Rating:  4.9 out of 5 stars   (55 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. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.


After one year, I think this was a good investment for my RX 350. I’ve used it several times now for various reasons, mostly towing my motorcycle. It was super easy to install and has held up pretty good so far. The only recommendation I have is to run your wiring from the interior fuse box with a fuse tap, rather than running it under the car from the battery. Running the wiring along under carriage just seemed like a bad idea long term. Just use one of the cigarette lighter fuses in the fuse box to tap onto and route the wiring along the interior panels. The hardest part is getting past the rear seat. I recommend using a wire hanger for this part. Great product overall!


The harness was for a Lexus 2004 RX330. A local auto detail shop did the wiring, as electrical is a DIY area that I don't enter. They installed it one afternoon in August 2021. It has operated the lights on a small boat trailer over a number of mountain passes and at lake launch areas without any glitches. Nice!!!

Really like the website for searches and support videos, knowledgebase info. Emphasis on competent, thoughtful customer service. I'll order here again.


E-Trailers did a great job of making this process easy! The video of their installer putting this exact kit in my exact car was so well done that even I could do it safely and competently. My car became so much more useful in just a couple hours that it’s probably one of the best investments I’ve made in years. Thanks, eTrailer for the great product, quick service, great communication and attention to detail!

2007 Lexus RX 350

When I first opened the box and saw how sturdy and heavy this received was, I thought maybe I was in over my head doing the install myself. However, I was able to easily balance the receiver on a spare tire/wheel I laid on the ground in the middle/back of my vehicle. That allowed me to easily lift the unit high enough t get a bolt started the muffler side, then it was a simple matter of installing the rest of the bolts, it took me no more than 20 minutes, including removal of the old tie-down brackets. I towed with it today, everything is great. I also learned that my 2007 Lexus RX350 came pre-wired for a trailer, all I had to do was tear off some interior trim, the wires were clearly visible, I cut off the proprietary connectors and sliced in a 4-wire cable. I'm not sure if they call come this way.


Hitch came early.Nice fit and finish.Hardware was included so was able to install inabout 15 minutes. Would recommend to anyone looking for a hitch for a great price.

2009 Lexus RX 350

The unit itself is good and seems to function well. My only issue is with the installation video from Curt. We put the unit in a 2009 RX350 and while it is correct for the car, they used a newer car for the video and it has significant assembly differences which adds time to the install to figure them out.


Excellent product! Installed as described in the instructions included with the product. Would buy this product again.

It is working perfectly!
Dale - 05/06/2022


Easy set up for people without electrical experience, just follow the inatructions/video & you'll be fine!

2009 Lexus RX 350

etrailer had the exact information I needed on how to order and get the product(s) I needed. Very easy to find, understand, order and receive. Everything went great

Great-just what I needed and wanted
R.P. R - 04/29/2021

2008 Lexus RX 350

I installed the wiring harness part # C55563 for the 2008 Lexus RX350. I watched the video which was specific to my vehicle and had a good idea of how to proceed. By following each step as it was explained I was able to complete the install in about 4 hours. It took me longer than most people because I had to keep going in the house and looking at the video. I was very happy with the way everything went together and pleased that all parts that I needed were included. It is a little hard working in confined area around the taillight but take your time and don't be afraid to pull back on the trim is needed. It is also good to have a trim tool to pull the push pins and have some extra push pins on hand in case you break one.

Lexus RX 350

This was the first time I had ordered a product from etrailer and my experience has been awesome. I started by googling a hitch for my 09' Lexus RX350 and wasn't sure if such a thing existed. etrailer was the first on the search engine. The website made it easy to navigate what products I was looking for.

I was looking for a complete kit which included a custom fit hitch. Browsing through the website and reading through the descriptions, I found out that I also needed a wiring set. etrailer made it easy to search for wiring kits with great prices.

The wiring kit came in the exact time frame along with the rest of my order and still in factory packaging. I am thankful for the instruction videos that etrailer provides because that made the installation that much easier. Me and my father followed the instruction video step by step and was able to have the wiring installed in about 30 to 45 minutes. I read from previous reviews that the length of the battery connector might be short but in my case, it was more than enough to reach the battery on my 09' Lexus RX 350.

This is my first wiring kit and although I haven't used it, I'm excited to try it for my move in the next two months. Overall, great product with easy installation. I'd recommend it to anyone wanting to get it for your 09' Lexus RX350.

2005 Lexus RX 330

Nice hitch. Exactly as the web described. Easy installation even for a single person lying on the floor of the garage. Wiring harness fairly easy installation even though it seemed a little shorter than displayed in the video. Double face tape would not stick even after cleaning car with alcohol. Wire tied to car wiring for installation just as well.
Purchased self tester and would recommend this for a lone person installation. All total took about 3 hours.

2006 Lexus RX 330

100% satisfied......excellant hitch...bolted right up...easy peezy...wiring harness right on the nuts, took a bit to string it but with some backyard mechanical ability you can git-er-done 2006 Lexus 360


The website was very easy to navigate. The videos to show insulation were very helpful. The additional information in regards to additional recommended products was helpful. I would recommend this to anybody looking for a light kit and hitch system.

2004 Lexus RX 330

If it is a DIY application, etrailer is my go to source forever. I added a towing/hitch system to my 2004 Lexus RX 330 in the Driveway. Easy install.

2004 Lexus RX 330

Great product - My vehicle is a 2004 lexus rx330 which required a long wire all the way from the battery back to the rear lights . Care must be taken as the wire is routed to make sure that there is no chance of the wire rubbing on anything over time and wearing through , which would then blow a fuse or worse . Despite that concern , I've no problems at all .

Thanks , John


Item was delivered promptly, the you tube installation video was great and essential. Getting the connectors on the car apart is not real easy but doable. Works as advertised.


The kit had everything needed to set up wiring. Quality materials and good instruction. Snap fit at the light connections made it fool proof. The toughest part of the project was routing the wire to the battery, but the wire was extra long so one could route it s number of ways. I chose to go over the gas tank. Highly recommend.

2008 Lexus RX 350

Always great service- online videos are extremely helpful.... Hitch and harness installed w ease

2007 Lexus RX 350

This wiring harness worked perfectly for my 2007 Lexus RX 350. Everything that I needed was included and it couldn't have been more simple.

2005 Lexus RX-330

Good quality wire harness. All the parts are included. The instructions are clear.

2006 Lexus RX 330

Good quality harness. Pretty simple to install with the exception of the power wire. A car lift is helpful to run and secure the wire to the battery.

2006 Lexus RX 330

Bolted right on and the lighting kit worked great!

2008 Lexus RX 350

Kit had everything to make installation easy & uncomplicated. Great instructions provided.


Not a good review to use. I ordered the wrong part for my suv. I ended up with a tow package on my car so I reordered the right part. Return was easy

Show More Reviews

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

  • Running Wire to Battery for Installation of Curt Wiring Harness on 2005 Lexus RX 330
    Many vehicles, like your 2005 Lexus RX 330, require a hot lead wire to be run up to the positive post of the battery when installing a trailer wiring harness such as the Curt T-Connector Harness # C55563. This is needed to protect the delicate wiring inside your vehicle. By pulling its voltage from the battery, if there is a short anywhere on your trailer, it will not overdraw the vehicle's wiring and potentially damage something. Any needed repairs on a vehicle's wiring system can be very...
    view full answer...
  • Grounding Curt T-Connector Wiring Harness on 2005 Lexus RX 330
    The Curt T-Connector Vehicle Wiring Harness # C55563 referenced in your question, which is confirmed to fit your 2005 Lexus RX 330, does have white wires on either side of the converter box. These are the ground wires, however the ground is already in the connector that runs to the existing driver and passenger side taillight ports on the vehicle. You will not need to ground the box beyond making these connections. I have attached the complete written installation details on this harness...
    view full answer...
  • Does Curt Trailer Wiring Harness 55563 Fit a 2011 Lexus RX 350
    Curt trailer wiring harness # C55563 is indeed listed as a fit for your 2011 Lexus RX 350 though it is an older harness. A vehicle side 4-Way has a ground pin, running light pin, left turn signal/brake light pin, and right turn signal/brake light pin. The converter box takes the separate circuits from the vehicle and combines them for use on the trailer. So basically on the vehicle for input there are white wires for ground, brown for running lights, yellow for left turn signal, green...
    view full answer...
  • Does Curt Trailer Wiring Harness # C55563 Need to be Grounded
    The white wires on either side of the converter box are ground wires. The ground is already in the connector that runs to the driver side taillight harness so you would not need to ground the box beyond that.
    view full answer...
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  • Trailer Wiring Harness Recommendation for a 2008 Lexus RX 350
    The closest thing I can recommend to a plug in trailer wiring harness for your 2008 Lexus RX 350 would be the Curt Wiring Harness part # C55563. This harness plugs in line with your vehicle taillight harnesses and does not require any wire cutting or splicing besides running a power wire up the vehicle battery. I attached install instructions and an FAQ on routing the power wire for you to check out.
    view full answer...
  • No Power Using the Curt Vehicle Wiring Harness Part # 56083 on a 2010 Lexus RX 350
    The Curt T-Connector Vehicle Wiring Harness part # 56083 that you installed on your 2010 Lexus RX 350 will only work on models with the factory tow package. If you do not have the factory tow package then the correct harness for you would be the Curt T-Connector Vehicle Wiring Harness part # C55563. This option will attach directly to the battery for power as you can see in the attached install video. If you have called the dealer with your VIN and confirmed that you do indeed have the...
    view full answer...
  • Recommended Trailer Wiring Harness for 2007 Lexus RX 350
    For your 2007 Lexus RX 350 I definitely recommend going with the Tekonsha T-One Wiring Harness # 118478. The Tekonsha harness, like you mentioned, provides a more secure ground connection to the vehicle. Tekonsha is also more well known for making durable and reliable trailer electrical products. I can tell you that we see far fewer troubleshooting questions on Tekonsha harnesses than we do with those from any other manufacturer, including Curt. This custom harness installs by plugging...
    view full answer...
  • Odd Voltage Readings and Malfunctioning Trailer Lights w/Curt Harness Installed on 2004 Lexus RX330
    It sounds like the converter box may have shorted out, which can cause high and low voltage readings. To verify this, you will want to test the power going into and out of the converter box. If all power readings are fine going into the box but not coming out of the converter, then we'll know it is a problem with the box and not an issue with your Lexus. I've provided a link to our article on troubleshooting 4 & 5-way wiring installations which may be helpful. It is most likely a short...
    view full answer...
  • How to Access Wiring for 2009 Lexus RX 350
    If you have the factory tow package then you can access that port behind the drivers side in the hatch of your 2009 Lexus RX 350 to install 4-way harness # 18002. Harnesses # C55563 and # 118478 can still be used, and will provide higher current with protection for the car's wiring I've added a link to a video review of this part being installed on an '07 RX 350 for you to check out which will be the same as your '09.
    view full answer...
  • 2005 Lexus RX 330 Trailer Hitch Recommendation
    All three of the hitches recommended for your 2005 Lexus RX330, the Curt Hitch part # 13530 and the Draw Tite Hitch part # 75153 will not interfere with the spare tire of your vehicle. It will install and remove on your vehicle just like normal. If you plan on doing some towing you might be interested in etrailer ball mount kit # 989900. It comes with 2 ball mounts; one with a 3/4 inch rise or 2 inch drop and one with a 2-3/4 inch rise or 4 inch drop. It also includes a 1-7/8 inch ball,...
    view full answer...
  • Factory Trailer Wiring for 2005 Lexus RX330
    I'm unaware that the RX330 was available with factory trailer wiring. Must be a pretty rare option. The photo you provided certainly shows a 4-pole trailer connector. If the wiring harness shown in the photo came with your RX330 when it was new, then there should be a connector somewhere at the rear of the vehicle for the harness to plug in. It looks like there's a grommet on the harness, so the connector might be behind the side panels in the cargo area or in the well where the spare...
    view full answer...
    Image 1 for
  • Instructions For Installing Wiring Harness On 2010 Lexus RX 350
    I am attaching the instructions for the Curt T-Connector Vehicle Wiring Harness, part # C55563 for your 2010 Lexus RX350. As the instructions say, you will need to remove the access panels on each side of the rear area and then remove the rear hatch threshold plate. You will then need to locate the vehicle harness behind the access panel. Check out the connectors on the Curt harness and find the connectors that match. Then disconnect the vehicle connector on the driver side. Insert the...
    view full answer...
  • Which Hitch for the 2009 Lexus RX350 Sticks out the Least
    It looks like the Curt trailer hitch # 13530 extends the least past the rear bumper. If you check out the picture I attached you will see that it sticks out the least. To complete your towing setup you may be interested in the following products: etrailer Ball Mounts # 989900 Curt Custom Fit Vehicle Wiring # C55563
    view full answer...
    Image 1 for
  • Hitch and Wiring Installation on 2007 Lexus RX350 With Factory Towing Prep Package
    Exactly what constitutes a towing prep package can vary widely among vehicle makers and models and can depend on whether the additional equipment was factory- or dealer-installed. Sometimes a 'tow-package-equipped' vehicle may still need fuses and/or relays installed to activate the wiring. There is a good chance the wiring is in place already. You can check under your rear bumper for any signs of wiring for a trailer connector and test them using a circuit tester like # PTW2993, or you...
    view full answer...
  • Plug and Play Trailer Wiring Harness for a 2011 Lexus RX 350 with Factory Tow Package Plug
    You can test that connector you found on your 2011 Lexus RX350 to determine if it is indeed a connection point for trailer wiring and if it is active. Use a circuit tester such as # PTW2993 to test the connector while someone goes through the lighting functions in the cab of the vehicle. If it has power, then you could use harness # 118252.
    view full answer...
  • Recommended 2-Inch Trailer Hitch Receiver for 2010 Lexus RX 350
    We offer three brands of Class III hitch for your 2010 Lexus RX 350 that can be seen on the linked page. All of them require SOME amount of trimming of the rear fascia but none requires any drilling. Between the options I recommend the Curt # C13143 because it is lowest in price and has a higher tongue weight capacity (600-lbs) than the Draw-Tite # 75676. All hitches include the required mounting hardware; written instructions, a video and an article on hitch installation are linked also. If...
    view full answer...
  • Brake Controller and Install Recommendation for a 2006 Lexus RX 330
    You will need two things to install a brake controller on your 2006 Lexus RX 330 that has a 4-way installed in it already. First you will need the part # ETBC7. This comes with everything needed to convert the 4-way to a 7-way and install a brake controller. Next you will need a brake controller. For a brake controller I would recommend the Prodigy P2 Brake Controller part # 90885. This is our best selling brake controller because of how well it works and how easy it is to setup. This...
    view full answer...
  • Least Expensive Trailer Hitch, Wiring Harness, and Brake Controller for 2009 Lexus RX 350
    I will give you a list of all the most budget-friendly parts for a complete towing set up for your 2009 Lexus RX 350. It sounds like you have a trailer with electric brakes, so you will need a hitch, 7-way, 4-way (which is needed because it plugs into the 7-way), ball mount, 2" hitch ball and brake controller. So here is the list of the most economical parts for you: - Curt Trailer Hitch Receiver # 13530 - Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # C55563 -...
    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 Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Jacob T
Video Edited:
Jacob T
Employee Cole B
Installed by:
Cole B
Employee Wilson B
Updated by:
Wilson B
Employee Kristina F
Updated by:
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Employee Isabelle B
Updated by:
Isabelle B
Employee Zach D
Video by:
Zach D
Employee Brent H
Test Fit:
Brent H

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