Trailer Wiring & Electrical Connection Installation – Manassas VA

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Electrical

Trailer Electrical Connection Installation – Manassas, VA

4-Pin, 7-Way, & Brake Controller Setup for Safe Towing

Before you hitch up your trailer, you need a reliable electrical connection between your towing vehicle and trailer. At American Truck & Trailer Supply in Manassas, Virginia, we install everything from basic 4-pin trailer plugs to 7-way RV connectors and trailer brake controllers—so you can tow legally, safely, and confidently.

Whether you’re towing a utility trailer, boat, camper, or enclosed hauler, we’ll make sure your electrical system is up to the task.

Types of Trailer Electrical Connections We Install

4-Pin Flat Trailer Connector

The most common wiring setup for light-duty trailers without brakes.

Supports:

  • Running lights

  • Brake lights

  • Left/right turn signals

  • Ground

Used for:

  • Utility trailers

  • Small cargo trailers

  • Jet ski, ATV, or lawn care trailers

7-Way Round RV Blade Connector

Required for trailers with electric brakes, this plug provides a full-power connection for all your trailer functions.

Supports:

  • All 4-pin functions

  • Trailer brake power

  • Auxiliary power (12V charge line)

  • Reverse lights (if installed on trailer)

Used for:

  • Travel trailers

  • Car haulers

  • Enclosed cargo trailers

  • Horse trailers & goosenecks

  • Toy haulers

We install OEM-style trailer connectors mounted to the rear bumper or hitch area, using weatherproof harnesses and junction boxes.

Do You Need a Trailer Brake Controller?

If your trailer has electric brakes, most states—including Virginia—require a working brake controller installed in the tow vehicle.

We install industry-trusted brands such as:

  • Tekonsha Prodigy series

  • CURT Echo & Spectrum

  • Redarc Tow-Pro Elite

  • Draw-Tite I-Command

  • Bluetooth-enabled

All brake controller installations are:

  • Professionally installed

  • Designed to work with 7-way connectors and electric-over-hydraulic setups

Additional Trailer Wiring Services

  • T-connector plug-and-play kits for late model trucks

  • Custom hardwired solutions for older vehicles

  • Adapter installation (7-way to 4-pin, and vice versa)

  • Breakaway switch wiring for trailers with brakes

  • Battery charge line integration

  • Fault diagnosis and wiring repairs

Compatible with All Vehicle Types

We wire trailers and towing systems for:

  • Ford F-150 / F-250 / Super Duty

  • Ram 1500–3500

  • Chevy Silverado / GMC Sierra

  • Toyota Tacoma / Tundra

  • Nissan Titan

  • SUVs and crossovers with towing packages

  • Commercial vehicles and fleets

Serving Manassas, VA and Northern Virginia

Conveniently located in Manassas, we proudly serve:

  • Gainesville

  • Bristow

  • Centreville

  • Haymarket

  • Warrenton

  • Nokesville

  • Fairfax

  • Sterling

  • Northern Virginia

Why Choose American Truck & Trailer Supply?

Full-Service Trailer Wiring Shop
4-Pin, 7-Way, and Brake Controller Specialists
Top Brands & OEM-Grade Wiring Components
Quick Turnaround & Professional Workmanship
Trusted by Northern Virginia’s Work Truck Owners & RVers

Get a Wiring Quote or Book an Install Today!

Towing a trailer? Don’t leave your electrical system to chance. Contact us today to get wired up the right way.

Location: 11949 Livingston Road, Manassas, Virginia
Phone: 703 257 1710