When your tow vehicle's trailer connector doesn't quite reach -- whether you're dealing with a longer hitch extension, a gooseneck setup, or just an awkward mounting position -- the CURT 56003 gives you seven additional feet of wiring without touching a single wire. This custom extension harness uses factory-style molded connectors on both ends for a clean, no-splice installation that preserves your vehicle's original wiring integrity.
The CURT 56003 is a purpose-built extension harness designed to solve one of the most common towing headaches: a trailer plug that simply doesn't reach. Whether your brake controller, connector mount, or hitch receiver is positioned further back than standard, this harness bridges the gap cleanly and safely.
CURT engineered this harness with molded, weatherproof connector ends that plug directly into your existing factory or aftermarket trailer wiring connector. One end plugs into the vehicle-side connector; the other presents a standard connector face for your trailer plug. The result is a transparent seven-foot extension that passes all trailer lighting and brake signals through without signal degradation under normal towing conditions.
Adds a full seven feet of reach between your tow vehicle's connector and the trailer plug -- enough to handle hitch extensions, step bumpers, and long-tail mounting positions.
Molded connector ends on both sides mean zero wire cutting, zero crimping, and zero splicing. Installs in seconds and removes just as fast when you need it.
CURT builds the 56003 with weather-resistant materials at the connector housings to handle road spray, rain, and the dirt and grime that comes with regular towing use.
Carries all standard trailer lighting circuits -- running lights, brake lights, turn signals, and ground -- through a full seven feet without voltage drop problems under normal towing loads.
CURT's custom wiring extensions are part of their broad trailer wiring accessories category, sitting alongside their T-connectors, adapters, and vehicle-specific harnesses. The 56003 is a universal-application extension rather than a vehicle-specific T-connector, meaning it is intended to extend an already-installed and compatible connector rather than replace your vehicle's OEM integration harness.
If your tow vehicle already has a working factory or CURT T-connector installed at the hitch, but the pigtail doesn't reach your trailer's connector when hitched up, the 56003 is exactly the part you need. It is commonly used alongside:
RV owners frequently run into connection-reach problems in a few specific situations. Travel trailer owners with a short factory pigtail on their tow vehicle often find the plug won't reach a trailer's connector when the trailer has a longer A-frame tongue. Fifth-wheel truck setups where the 7-way is mounted in the bed sometimes need a short extension to reach the king pin area wiring loom. The CURT 56003 handles all of these use cases.