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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. Powered converter reduces strain on wiring system and is made using SMT to ensure superior performance.
Features:
Specs:
Installation
This custom-fit T-connector plugs into your vehicle's wiring harness, which is located behind the tail light housings. You will have to remove interior trim paneling to access these connection points. 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.
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.
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.
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First, let me tell you that the wiring harness fits like a glove and was easy to install with the enclosed instructions.
Second, after I installed the kit on my 2024 Toyota Cross a "Check engine light" came on so I rechecked the install and could not find anything wrong. I took it to the local Toyota dealer and ran a diagnostic test and determined that it was not a Toyota issue and charged me about 300 bucks. It was determined that on one side of the wiring install I did I blocked one of the proximity sensors and they all had to be recalibrated at the tune of $400.00 more. I had the work done and returned home to see if I had misread the install instructions from etrailer and there was no mention of avoiding sensors.
I called etrailer and shared with them my situation and that I thought they should have mentioned in the instructions that for cars with the Proximity Sensor System, take caution NOT to block the rear sensors when you drop the wires down through the tail light cavity, and would they refund me the cost I incurred. They went from friendly to very stern in their reply and stated they would not but they would correct their instructions. The last time I checked, they had not.
Third, I have been a customer of etrailer for over 40 years and having a car lift in my garage, I have installed a lot of their hitches, wiring kits, weight distribution hitches, lights, brake controllers and many other things for myself and friends without ever having an instruction issue. I'm sure the rear and front mounted trailer hitches count is over 20, maybe 25.
Looks good. Arrived promptly Thank you
Perfect!
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Kate F.
9/3/2025
Hello Douglas, thank you for sharing your experience. I’m really sorry to hear about the frustration you’ve run into, I know I’d feel the same way in your shoes. Just to clarify, the installation instructions actually come directly from Curt, the manufacturer, so we aren’t able to make changes to them ourselves. I will look into this further.