{"product_id":"curt-4-way-flat-trailer-wiring-harness-for-ram-promaster-1500-2500-3500-vehicle-side-plug-and-play-with-dust-cover","title":"CURT 4-Way Flat Trailer Wiring Harness for Ram ProMaster 1500\/2500\/3500 - Vehicle-Side Plug-and-Play with Dust Cover","description":"\u003cp\u003e\u003cstrong\u003eCURT 56478 is a vehicle-side, plug-and-play 4-way flat trailer wiring harness built to give select Ram ProMaster 1500, 2500 and 3500 models a factory-style trailer connector without cutting or splicing.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf your ProMaster lacks a trailer connector, this custom CURT wiring harness provides a direct, OEM-compatible connection to run tail lights, brake lights and turn signals to a towed trailer. Designed to plug into the vehicle's taillight assembly, the harness includes a 4-way flat socket, a protective dust cover and a tail light converter with SMT circuitry for improved reliability. Installation is straightforward and reversible, making it an efficient solution whether you tow occasionally or regularly.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this harness simplify trailer wiring installation?\u003c\/h3\u003e\n\u003cp\u003eThe CURT 56478 harness is engineered as a custom-fit T-connector that plugs into existing vehicle taillight plugs, removing the need to access wiring, cut, splice, or solder. This reduces installation time and preserves factory wiring integrity.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eVehicle-specific connectors match factory taillight plugs for a secure fit.\u003c\/li\u003e\n  \u003cli\u003ePlug-and-play design installs without special tools or wire modifications.\u003c\/li\u003e\n  \u003cli\u003eIncludes a dust cover to protect the connector when unused.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat lighting functions does the 4-way flat provide?\u003c\/h3\u003e\n\u003cp\u003eThe 4-way flat socket delivers the standard trailer lighting signals: left and right turn signals, tail\/running lights, and brake lights. It's intended for basic trailer lighting and works with most small trailers, cargo carriers and boat trailers that use a 4-way flat connection.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eLeft and right turn signals pass through to the trailer.\u003c\/li\u003e\n  \u003cli\u003eBrake light and tail\/running light circuits are routed via the converter.\u003c\/li\u003e\n  \u003cli\u003eCompatible with trailers using the common 4-way flat standard.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat makes CURT's wiring durable and compatible with my vehicle?\u003c\/h3\u003e\n\u003cp\u003eCURT builds this harness with SMT (surface-mount technology) circuitry and vehicle-specific terminals to enhance electrical stability and resist vibration and corrosion. The included tail light converter conditions signals so the vehicle and trailer communicate reliably.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSMT circuitry improves performance under vibration and temperature changes.\u003c\/li\u003e\n  \u003cli\u003eOEM-style connectors ensure a snug, interference-free fit in taillight sockets.\u003c\/li\u003e\n  \u003cli\u003eDust cover and weather-resistant components extend connector life.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this harness fit my Ram ProMaster and what should I check before buying?\u003c\/h3\u003e\n\u003cp\u003eThe CURT 56478 is made to fit specific model years and trims of the Ram ProMaster 1500, 2500 and 3500. Before purchasing, verify vehicle compatibility using the application chart or by matching the factory taillight connector to the harness plugs.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eConfirm model year and trim compatibility in the product application guide.\u003c\/li\u003e\n  \u003cli\u003eInspect your taillight assembly plug to ensure it matches the harness connectors.\u003c\/li\u003e\n  \u003cli\u003eProfessional installation is quick; do-it-yourself installation is possible for experienced owners.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: The CURT 56478 wiring harness is ideal for Ram ProMaster owners who need a reliable, no-drill electrical connection to tow trailers with a 4-way flat plug. It's a smart choice for tradespeople, weekend campers, boat owners and anyone who wants a clean, factory-style trailer socket without altering vehicle wiring.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does this harness require cutting vehicle wires?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No. The CURT 56478 plugs into factory taillight connectors—no cutting or splicing required.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this for trailers with brake and turn signals?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The 4-way flat carries turn signals, brake lights and tail\/running lights for standard trailers.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"CURT","offers":[{"title":"Default Title","offer_id":67585444675769,"sku":"B0BGS9XFYY","price":201.33,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0822\/3765\/3177\/files\/curt-56478-front-view-connector.jpg?v=1790470360","url":"https:\/\/redleafauto.ca\/products\/curt-4-way-flat-trailer-wiring-harness-for-ram-promaster-1500-2500-3500-vehicle-side-plug-and-play-with-dust-cover","provider":"Redleaf Auto","version":"1.0","type":"link"}