CURT 4-Pin Trailer Wiring for Subaru Ascent/Forester/Outback/Crosstrek — Plug-and-Play 4-Way Flat

CURT 56040 is a vehicle‑specific 4‑pin plug‑and‑play trailer wiring connector designed to give compatible Subaru Ascent, Forester, Outback and Crosstrek models a standard 4‑way flat trailer socket without cutting or splicing the factory wiring.

If you tow small trailers, utility carts, or recreational gear with a compatible Subaru, this CURT T‑connector delivers a professional wiring interface that installs in minutes. The harness mates to the vehicle’s OEM socket (where equipped) and outputs a 4‑way flat connection that carries tail lights, turn signals and brake lights. Built with SMT circuitry and a tail light converter, the 56040 is engineered to match factory electrical behavior and resist the wear of regular towing use.

How does this connector install on my Subaru?

Installation is plug‑and‑play when your Subaru has the required OEM socket. There’s no cutting, splicing, or soldering: the harness plugs into the vehicle connector and routes to the rear bumper area where the 4‑way flat socket mounts. CURT includes the mounting hardware and a dust cover so the socket stays protected when not in use.

• Plugs into factory OEM trailer socket (if vehicle equipped)
• No wire cutting or splicing required
• Mounting bracket and hardware included for secure fit
• Protective dust cover keeps socket clean

What lighting functions does the 4‑way flat provide?

The 4‑way flat output carries the essential trailer lighting signals: running/tail lights, left and right turn signals, and brake lights. A built‑in tail light converter ensures the Subaru’s lighting circuits and the trailer’s wiring behave compatibly, avoiding bulb conflicts or abnormal flash patterns.

• Tail/running light feed for nighttime visibility
• Separate left and right turn signal circuits
• Brake light output synchronized with vehicle brakes
• Integrated converter to protect vehicle lighting circuits

Will this harness work reliably over time and in wet conditions?

CURT designs these custom harnesses with durable components and SMT (surface‑mount technology) circuitry to improve long‑term performance and reduce failures from vibration. The connector includes a weather‑resistant dust cover and robust contacts to maintain a consistent electrical connection during routine use.

• SMT circuitry for improved durability and signal stability
• Sealed connector contacts reduce corrosion risk
• Dust cover prevents debris and moisture ingress when unused
• Tested by CURT for reliable vehicle‑to‑trailer operation

Which Subaru models and years does this fit?

The CURT 56040 is made to match the wiring interface for specific model years of Subaru Ascent, Forester, Outback, Crosstrek and XV Crosstrek. Because vehicle wiring and factory sockets vary by year and trim, verify compatibility with the vehicle application information before purchase to ensure a correct fit.

• Custom‑fit for select Subaru Ascent, Forester, Outback, Crosstrek and XV models
• Check product application guide for exact model years and trims
• Designed to match OEM connector locations and mounting points
• Hardware included for secure, vehicle‑specific installation

Who is this for: The CURT 56040 is aimed at Subaru owners who tow light trailers, small utility loads, or recreational gear and who want a factory‑style wiring connection without modifying the vehicle’s factory wiring. If you value a clean, reversible install and dependable trailer light signaling, this custom T‑connector is a straightforward, professionally engineered solution.