2021 Subaru Legacy Trailer Wiring

Please Select your Vehicle to See Exact Fit Parts

Keep Your 2021 Subaru Legacy in Top Shape with a Quality Trailer Wiring

When it comes to maintaining or upgrading your 2021 Subaru Legacy, choosing high-quality parts is crucial for ensuring your vehicle stays in top shape, whether you’re tackling a repair or enhancing performance. At Advance Auto Parts, we know how important it is to find the right Trailer Wiring for your Legacy. We currently carry a top Trailer Wiring in stock that is built to last. Whether you’re replacing a damaged Trailer Wiring or looking to upgrade, our selection for the 2021 Subaru Legacy ensures you’ll find exactly what you need to keep your vehicle looking and performing its best.

Explore Related Parts

And while you’re here, don’t forget to check out related part categories like Trailer Hitches to complete your upgrade or repair project. At Advance Auto Parts, we’re proud to offer the parts and expertise to keep your 2021 Subaru Legacy running smoothly and looking great.

Essential 2021 Subaru Legacy Trailer Wiring

CURT – CURT Replacement OE 7-Way RV Blade Socket (Plugs into USCAR), 55415 (Part No.55415)

CURT Replacement OE 7-Way RV Blade Socket (Plugs into USCAR), 55415

from

$22.99
Like trailer hitches and ball mounts, electrical connectors range all over the board in shape, size and capability, but no matter what your trailer’s electrical functions are, you need a solid connection to keep the power flowing and ensure safety on the road. CURT electrical connectors are designed and manufactured to give you a reliable connection every time you plug in your trailer. This 7-way RV blade connector is designed to plug into a USCAR socket and supply power for tail lights, turn signals, electric trailer brakes, a 12-volt battery, reverse lights and brake lights, as well as a ground connection. It is intended to be a replacement trailer connector, plugging into a standard USCAR socket (see application info to verify fitment with your vehicle). It features rust-free black plastic construction and comes with a spring-loaded cover to keep out dust and water. This 7-way RV blade connector is a female-end socket, specifically designed for the vehicle side of the connection.
See More

CURT – CURT 7ft. Custom Wiring Harness Extensions Adds 7-Way RV Blade to Truck Bed 10-Pack, 56070010 (Part No.56070010)

CURT 7ft. Custom Wiring Harness Extensions Adds 7-Way RV Blade to Truck Bed 10-Pack, 56070010

from

$972.99
There is nothing like the luxury and power that go along with heavy-duty towing. 5th wheel RVs offer a deluxe, home-away-from-home experience unlike any other, while gooseneck trailers possess a strength that far surpasses most other trailer options. As with any trailer, however, 5th wheels and goosenecks must be equipped with the proper lighting and electrical systems, and tend to require even more complex connectors than a standard receiver-type trailer setup. Make things simple with a CURT 5th wheel / gooseneck extension harness. These wiring harnesses are designed to put an extra connector socket in the bed of your pickup truck while still retaining power to the rear connector socket mounted on your bumper or trailer hitch. This is done by plugging into the back of the existing original equipment (OEM) harness and routing through the body of the truck to a hole in the truck bed, providing a connector that is ready to accommodate your 5th wheel or gooseneck trailer. These CURT extension harnesses are designed to work with 7-way RV blade connectors and come with 7′ of wire. Ten harnesses are included in each package. They are compatible with certain models of Chevrolet, Dodge, Ford, GMC, Nissan, Ram and Toyota (see application to verify fitment). When you need a towing electrical solution that allows you to switch back and forth between your receiver hitch and specialized trailer hitch, CURT gets you plugged in.
See More

CURT – CURT 10ft. Custom Wiring Harness Extensions Adds 7-Way RV Blade to Truck Bed 10-Pack, 56000010 (Part No.56000010)

CURT 10ft. Custom Wiring Harness Extensions Adds 7-Way RV Blade to Truck Bed 10-Pack, 56000010

from

$1023.00
There is nothing like the luxury and power that go along with heavy-duty towing. 5th wheel RVs offer a deluxe, home-away-from-home experience unlike any other, while gooseneck trailers possess a strength that far surpasses most other trailer options. As with any trailer, however, 5th wheels and goosenecks must be equipped with the proper lighting and electrical systems, and tend to require even more complex connectors than a standard receiver-type trailer setup. Make things simple with a CURT 5th wheel / gooseneck extension harness. These wiring harnesses are designed to put an extra connector socket in the bed of your pickup truck while still retaining power to the rear connector socket mounted on your bumper or trailer hitch. This is done by plugging into the back of the existing original equipment (OEM) harness and routing through the body of the truck to a hole in the truck bed, providing a connector that is ready to accommodate your 5th wheel or gooseneck trailer. These CURT extension harnesses are designed to work with 7-way RV blade connectors and come with 10′ of wire. Ten harnesses are included in each package. They are compatible with certain models of Chevrolet, Dodge, Ford, GMC, Nissan, Ram and Toyota (see application to verify fitment). When you need a towing electrical solution that allows you to switch back and forth between your receiver hitch and specialized trailer hitch, CURT gets you plugged in.
See More

CURT – CURT Custom Wiring Harness, 56444 (Part No.56444)

CURT Custom Wiring Harness, 56444

from

$111.99
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution. A custom wiring harness — also called a T-connector — is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection. This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation. Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing. This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Subaru Legacy (to verify your vehicle compatibility, see application info). It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use. You have a picture in mind of your next destination — maybe it’s the boat landing at your favorite fishing spot, maybe it’s a campsite that overlooks one of nature’s masterpieces, or maybe it’s the next big jobsite. However, turning that picture into a reality takes more than just daydreaming. It takes a solid connection and the right amount of power. CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup.
See More

CURT – CURT Replacement USCAR Socket with 24in. Wires (Vehicle Side), 56229 (Part No.56229)

CURT Replacement USCAR Socket with 24in. Wires (Vehicle Side), 56229

from

$26.99
“Like trailer hitches and ball mounts, electrical connectors range all over the board in shape, size and capability, but no matter what your trailer’s electrical functions are, you need a solid connection to keep the power flowing and ensure safety on the road. CURT electrical connectors are designed and manufactured to give you a reliable connection every time you plug in your trailer. This 7-way USCAR replacement harness is designed to replace an existing USCAR plug and supply power for tail lights, turn signals, electric trailer brakes, a battery, reverse lights and brake lights, as well as a ground connection. It features rust-free black plastic construction and comes with color-coded wires and 24″” of bonded wire for easy splicing into your vehicle’s wiring system. This 7-way USCAR connector is a female-end socket, specifically designed for the vehicle side of the connection.”
See More

CURT – CURT Heavy-Duty Replacement OE 7-Way RV Blade Socket (Plugs into USCAR), 55416 (Part No.55416)

CURT Heavy-Duty Replacement OE 7-Way RV Blade Socket (Plugs into USCAR), 55416

from

$22.99
Like trailer hitches and ball mounts, electrical connectors range all over the board in shape, size and capability, but no matter what your trailer’s electrical functions are, you need a solid connection to keep the power flowing and ensure safety on the road. CURT electrical connectors are designed and manufactured to give you a reliable connection every time you plug in your trailer. This 7-way RV blade connector is designed to plug into a USCAR socket and supply power for tail lights, turn signals, electric trailer brakes, a 12-volt battery, reverse lights and brake lights, as well as a ground connection. It is intended to be a replacement trailer wiring connector, plugging into a standard USCAR socket (see application info to verify fitment with your vehicle). It features rust-free black plastic construction and comes with a spring-loaded cover to keep out dust and water. This 7-way RV blade connector is a female-end socket, specifically designed for the vehicle side of the connection (see application info to verify fitment with your vehicle).
See More

Carquest Premium – Carquest Trailer Connector Kit, TCC1389 (Part No.TCC1389)

Carquest Trailer Connector Kit, TCC1389

from

$199.99
Modern vehicles may have 100 or more electrical harness connectors in every operating system of the vehicle. Terminal tension may weaken with time or corrosion may occur within the connector housing making replacement necessary. When replacing any harness-connector assembly approved wire termination methods must be followed to ensure a successful and long-term solution to the original problem is made. A failed terminal connection, terminal corrosion or damaged wire will result in an electrical system fault.
See More

CURT – CURT Custom Wiring Harness, 4-Way Flat Output, Select Subaru Legacy sedan, 56091 (Part No.56091)

CURT Custom Wiring Harness, 4-Way Flat Output, Select Subaru Legacy sedan, 56091

from

$79.99
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution. A custom wiring harness — also called a T-connector — is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection. This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation. Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing. This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Subaru Legacy sedan (to verify your vehicle compatibility, see application info). It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use. You have a picture in mind of your next destination — maybe it’s the boat landing at your favorite fishing spot, maybe it’s a campsite that overlooks one of nature’s masterpieces, or maybe it’s the next big jobsite. However, turning that picture into a reality takes more than just daydreaming. It takes a solid connection and the right amount of power. CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup.
See More

CURT – CURT Custom Wiring Harness (4-Way Flat Output), 56380 (Part No.56380)

CURT Custom Wiring Harness (4-Way Flat Output), 56380

from

$103.99
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution. A custom wiring harness — also called a T-connector — is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection. This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation. Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing. This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Volkswagen Beetle (to verify your vehicle compatibility, see application info). It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use. You have a picture in mind of your next destination — maybe it’s the boat landing at your favorite fishing spot, maybe it’s a campsite that overlooks one of nature’s masterpieces, or maybe it’s the next big jobsite. However, turning that picture into a reality takes more than just daydreaming. It takes a solid connection and the right amount of power. CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup.
See More

CURT – CURT Custom Wiring Connector (4-Way Flat Output OEM Tow Package Required), 55370 (Part No.55370)

CURT Custom Wiring Connector (4-Way Flat Output OEM Tow Package Required), 55370

from

$37.99
CURT custom wiring connectors are the easiest way to outfit your vehicle with a CURT trailer wiring connection. They are built with some of the most advanced technology in the industry, and each one is custom-fitted to work with a specific make and model. Some automotive manufacturers install a special socket on the vehicle to be used for vehicle-to-trailer wiring. Although this special socket is not equipped on every vehicle, a CURT custom wiring connector — also called a T-connector — utilizes the socket for simple, stress-free installation. Rather than requiring you to cut, splice and solder into your vehicle’s wiring system, the custom wiring connector uses a single OEM-compatible plug and instantly provides a standard, universal vehicle-to-trailer wiring connection, typically in the form a 4-way flat. All CURT custom wiring connectors are made vehicle-specific for the easiest possible installation and the best fit. This particular plug-in connector provides a 4-way flat socket and is designed to be a custom wiring option for certain years of the Subaru Forester, Legacy, Outback wagon, Tribeca, B9 Tribeca and Impreza WRX wagon (factory tow package required; to verify your vehicle compatibility, see application info). It comes with all necessary hardware to establish a solid connection. It also comes with a dust cover to keep the connector socket clean when not in use. To ensure long-lasting reliability, all CURT custom wiring connectors are thoroughly tested for optimal functionality. Stress is the last thing you should feel when towing a trailer — whether you’re hauling your RV to that favorite camping destination, your ATVs up to the hunting grounds or your fishing boat to the new hidden hotspot. At CURT, we think your towing equipment should add to the enjoyment of your experience, not detract from it.
See More

CURT – CURT Replacement OE 4-Way Flat Socket (T s into USCAR), 55384 (Part No.55384)

CURT Replacement OE 4-Way Flat Socket (T s into USCAR), 55384

from

$41.99
Stress is the last thing you should feel when towing a trailer — whether you’re hauling your RV to that favorite camping destination, your ATVs up to the hunting grounds or your fishing boat to the new hidden hotspot. At CURT, we think your towing equipment should add to the enjoyment of your experience, not detract from it. CURT custom wiring connectors are the easiest way to outfit your vehicle with a CURT trailer wiring connection. They are built with some of the most advanced technology in the industry, and each one is custom-fitted to work with a specific make and model. Some automotive manufacturers install a special socket on the vehicle to be used for vehicle-to-trailer wiring. Though this special socket is not equipped on every vehicle, a CURT custom wiring connector (also called a T-connector) utilizes the socket for simple, stress-free installation. Rather than requiring you to cut, splice and solder into your vehicle’s wiring system, the custom wiring connector uses a single OEM-compatible plug and instantly provides a standard vehicle-to-trailer wiring connection, typically in the form a 4-way flat. All CURT custom wiring connectors are made vehicle-specific for the easiest possible installation and the best fit. This particular connector provides a 4-way flat socket while retaining use of the existing OEM socket. It is designed to be a custom wiring option for a variety of vehicles (see application info to verify fitment with your vehicle). It comes with a dust cover to keep the connector socket clean when not in use.
See More

CURT – CURT 10ft. Custom Wiring Harness Extension (Adds 7-Way RV Blade to Truck Bed), 56000 (Part No.56000)

CURT 10ft. Custom Wiring Harness Extension (Adds 7-Way RV Blade to Truck Bed), 56000

from

$154.99
There is nothing like the luxury and power that go along with heavy-duty towing. 5th wheel RVs offer a deluxe, home-away-from-home experience unlike any other, while gooseneck trailers possess a strength that far surpasses most other trailer options. As with any trailer, however, 5th wheels and goosenecks must be equipped with the proper lighting and electrical systems, and tend to require even more complex connectors than a standard receiver-type trailer setup. Make things simple with a CURT 5th wheel / gooseneck extension harness. These wiring harnesses are designed to put an extra connector socket in the bed of your pickup truck while still retaining power to the rear connector socket mounted on your bumper. This is done by plugging into the back of the existing original equipment (OEM) harness and routing through the body of the truck to a hole in the truck bed, providing a connector that is ready to accommodate your 5th wheel or gooseneck trailer. This CURT extension harness is designed to work with 7-way RV blade connectors and comes in a length of 10′. It is compatible with certain models of Chevrolet, Dodge, Ford, GMC, Nissan, Ram and Toyota (see application to verify fitment). When you need a towing electrical solution that allows you to switch back and forth between your receiver hitch and specialized trailer hitch, CURT gets you plugged in.
See More

CURT – CURT Custom Wiring Harness (4-Way Flat Output), 56246 (Part No.56246)

CURT Custom Wiring Harness (4-Way Flat Output), 56246

from

$92.99
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution. A custom wiring harness — also called a T-connector — is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection. This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation. Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing. This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Subaru Legacy (to verify your vehicle compatibility, see application info). It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use. You have a picture in mind of your next destination — maybe it’s the boat landing at your favorite fishing spot, maybe it’s a campsite that overlooks one of nature’s masterpieces, or maybe it’s the next big jobsite. However, turning that picture into a reality takes more than just daydreaming. It takes a solid connection and the right amount of power. CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup.
See More

CURT – CURT 7ft. Custom Wiring Harness Extension Adds 7-Way RV Blade to Truck Bed Packaged, 56070 (Part No.56070)

CURT 7ft. Custom Wiring Harness Extension Adds 7-Way RV Blade to Truck Bed Packaged, 56070

from

$105.99
There is nothing like the luxury and power that go along with heavy-duty towing. 5th wheel RVs offer a deluxe, home-away-from-home experience unlike any other, while gooseneck trailers possess a strength that far surpasses most other trailer options. As with any trailer, however, 5th wheels and goosenecks must be equipped with the proper lighting and electrical systems, and tend to require even more complex connectors than a standard receiver-type trailer setup. Make things simple with a CURT 5th wheel / gooseneck extension harness. These wiring harnesses are designed to put an extra connector socket in the bed of your pickup truck while still retaining power to the rear connector socket mounted on your bumper. This is done by plugging into the back of the existing original equipment (OEM) harness and routing through the body of the truck to a hole in the truck bed, providing a connector that is ready to accommodate your 5th wheel or gooseneck trailer. This CURT extension harness is designed to work with 7-way RV blade connectors and comes in a length of 7′. It is compatible with a certain models of Chevrolet, Dodge, Ford, GMC, Nissan, Ram and Toyota (see application to verify fitment). When you need a towing electrical solution that allows you to switch back and forth between your receiver hitch and specialized trailer hitch, CURT gets you plugged in.
See More

Most Popular Trailer Wiring Kit for 2021 Subaru Legacies

Enhance your 2021 Subaru Legacy with this popular Trailer Wiring Kit we have in stock, for $111.99.

CURT – CURT Custom Wiring Harness, 56444 (Part No.56444)

CURT Custom Wiring Harness, 56444

from

$111.99
If your vehicle is not equipped with wiring for towing a trailer, CURT custom wiring is the ideal solution. A custom wiring harness — also called a T-connector — is a simple, plug-and-play electrical device that plugs into your automotive electric system and provides a standard, universal trailer wiring connection. This is done using two or more vehicle-specific, OEM-compatible connectors to plug into the taillight assembly, eliminating the need for cutting, splicing and soldering during installation. Custom wiring harnesses are made vehicle-specific, and while they are not available for all vehicles, they do offer one of the fastest, easiest and most secure ways to wire a vehicle for towing. This particular plug-in harness provides a 4-way flat connector socket and is designed to be a custom wiring harness to fit certain years of the Subaru Legacy (to verify your vehicle compatibility, see application info). It comes with all necessary wiring components to establish a reliable trailer wiring connection, as well as a dust cover to keep the connector clean when not in use. You have a picture in mind of your next destination — maybe it’s the boat landing at your favorite fishing spot, maybe it’s a campsite that overlooks one of nature’s masterpieces, or maybe it’s the next big jobsite. However, turning that picture into a reality takes more than just daydreaming. It takes a solid connection and the right amount of power. CURT custom wiring is made with some of the most sophisticated technology in the industry and is designed to install with ease, giving you a long-lasting electrical connection for your towing hitch setup.
See More

FAQs for 2021 Subaru Legacy Trailer Wirings

What’s the price range for 2021 Subaru Legacy Trailer Wiring?

We currently have just one Trailer Wiring for the 2021 Subaru Legacy in stock: CURT Custom Wiring Harness, 56444 and it costs $111.99.

Does Advance Auto Parts sell Trailer Wiring for other Subaru Legacy model years?

Yes, we carry Trailer Wiring for 22 model years of Subaru Legacies between 1996 and 2025. The following model years are the most popular for Trailer Wiring purchases: 2019, 2018, 2017, 2016, 2015, 2003, 2002, 2001, and 2000.

Does Advance Auto Parts sell Trailer Wiring for any other 2021 Subaru models?

Yes. We stock Trailer Wiring for 3 other popular 2021 Subaru models. Some of the most popular are 2021 Outback Trailer Wiring, 2021 Forester Trailer Wiring, 2021 Crosstrek Trailer Wiring, and 2021 Impreza Trailer Wiring.

What types of Trailer Wiring do you sell for my 2021 Subaru Legacy?

We currently have just 1 Trailer Wiring in stock for a 2021 Subaru Legacy, and as of 8/2/26, it is a Trailer Wiring Kit.

Can I get help with 2021 Subaru Legacy Trailer Wiring orders?

Contact our customer support team by chat or phone, through the help desk page, where you can find instant answers about Subaru Trailer Wiring and more.

What is your return policy for Subaru Legacy Trailer Wiring?

Advance Auto Parts keeps returns simple. For new Subaru Legacy Trailer Wiring and accessories, your online orders can be returned, in their original condition, within 45 days. For requirements, see the returns page.