{"product_id":"curt-4-way-flat-trailer-wiring-harness-for-ram-promaster-1500-2500-3500-plug-in-oem-fit-with-dust-cover","title":"CURT 4-Way Flat Trailer Wiring Harness for Ram ProMaster 1500\/2500\/3500 — Plug-in OEM Fit with Dust Cover","description":"\u003cp\u003e\u003cstrong\u003eCURT 56478 is a vehicle-side, plug-and-play 4-way flat trailer wiring harness engineered to fit select Ram ProMaster 1500, 2500, and 3500 models and provide a reliable trailer lighting connection without cutting or splicing.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eIf your ProMaster lacks factory trailer wiring, this custom-fit CURT harness delivers a fast, OEM-compatible solution. The harness uses vehicle-specific connectors that plug into the existing taillight sockets, supplying a standard 4-way flat output for tail lights, brake lights and turn signals. Designed for easy installation and durable operation, it includes a dust cover and built-in circuitry to ensure consistent performance on the road.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this harness install on my Ram ProMaster?\u003c\/h3\u003e\n\n\u003cp\u003eInstallation is straightforward: the harness uses the factory taillight connectors so there is no cutting, splicing, or soldering required. You remove the taillight access panel, unplug the vehicle connectors and plug in the CURT T-connector. The 4-way flat socket mounts near the hitch for convenient trailer connection.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eDirect plug-in to vehicle taillight assembly — no wire modifications\u003c\/li\u003e\n  \u003cli\u003eIncludes dust cover to protect the connector when unused\u003c\/li\u003e\n  \u003cli\u003eHardware and wiring included for a neat, secure routing\u003c\/li\u003e\n  \u003cli\u003eDesigned for specific ProMaster model years—check fitment\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat functions and wiring does the 4-way flat support?\u003c\/h3\u003e\n\n\u003cp\u003eThe CURT 4-way supplies standard lighting circuits required by most small trailers and utility trailers: running lights, turn signals and brake lights. It uses a tail light converter to adapt the vehicle signals to the trailer's wiring when needed, keeping the trailer lights synchronized with the van's outputs.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eRunning\/parking lights, left\/right turn signals, and stop lights\u003c\/li\u003e\n  \u003cli\u003e4-way flat connector compatible with common trailer plugs\u003c\/li\u003e\n  \u003cli\u003eBuilt-in tail light converter for signal compatibility\u003c\/li\u003e\n  \u003cli\u003eSMT circuitry for reliable signal processing and longevity\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWill this harness withstand regular towing and exposure?\u003c\/h3\u003e\n\n\u003cp\u003eCURT designs its vehicle-side harnesses for everyday towing conditions, using durable components and SMT circuitry to reduce failure points. The dust cover helps keep moisture and debris out of the connector, and the wiring and terminals are routed to minimize stress from movement or road impacts.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eSMT (surface-mount technology) circuitry for improved durability\u003c\/li\u003e\n  \u003cli\u003eProtective dust cap to keep connector clean and dry\u003c\/li\u003e\n  \u003cli\u003eRobust wiring and secure mounting points to resist vibration\u003c\/li\u003e\n  \u003cli\u003eOEM-compatible connectors to maintain factory-like fit and finish\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow do I confirm compatibility for my vehicle?\u003c\/h3\u003e\n\n\u003cp\u003eCompatibility depends on the ProMaster model year and trim; always verify fitment details before purchase. Check the product application list or enter your vehicle details on the retailer’s compatibility tool to ensure the CURT 56478 matches your specific ProMaster 1500, 2500, or 3500.\u003c\/p\u003e\n\n\u003cul\u003e\n  \u003cli\u003eVerify model year and trim against the application information\u003c\/li\u003e\n  \u003cli\u003eUse VIN or vehicle lookup tools where available for accuracy\u003c\/li\u003e\n  \u003cli\u003eContact CURT or your vendor if fitment questions remain\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for? The CURT 56478 harness is ideal for ProMaster owners who need a clean, factory-style trailer wiring solution without permanent modifications. It's suited for contractors, outdoor enthusiasts, and small-business van operators who tow trailers occasionally or frequently and prefer a secure, easy-to-install electrical hookup that maintains the vehicle’s original wiring integrity.\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 my vehicle wiring?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: No—CURT 56478 is a plug-and-play T-connector that uses the factory taillight plugs, so no cutting or splicing is needed.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Will this work with any trailer using a 4-way flat plug?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes, it provides a standard 4-way flat socket compatible with most small trailers and utility trailers.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"CURT","offers":[{"title":"Default Title","offer_id":48081554112670,"sku":"B0BGS9XFYY","price":154.64,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0781\/2041\/9486\/files\/curt-56478-front-connector-overview.jpg?v=1785807896","url":"https:\/\/northtrailauto.ca\/products\/curt-4-way-flat-trailer-wiring-harness-for-ram-promaster-1500-2500-3500-plug-in-oem-fit-with-dust-cover","provider":"North Trail Auto","version":"1.0","type":"link"}