Baja Designs Automotive RTL Wiring Harness (Running / Brake / Reverse)

Universal Fit | Part Number: 640127

Power your rear lighting system the right way with the Baja Designs Automotive RTL Wiring Harness. Designed specifically for RTL rear light bars, this harness provides a complete, reliable solution for powering all lighting functions on your vehicle.

This harness is built to reach the rear of your truck or SUV and includes a relay and heavy-duty wiring to support all RTL functions, including running light, brake light, and reverse/cargo light. 

Engineered for durability and ease of installation, it delivers a clean, professional wiring setup for off-road, overland, and daily-driven builds.

Key Features

• Universal automotive fitment
• Part Number: 640127
• Designed for Baja Designs RTL rear light bars
• Supports running, brake, and reverse/cargo light functions
• Includes relay and inline fuse protection
• Extended length to reach rear mounting locations
• Heavy-duty wiring and protective sheathing
• Weather-resistant connectors
• Clean and reliable installation solution
• Limited lifetime warranty

⚠️ Fitment Note (IMPORTANT)

❗ Designed for Baja Designs RTL light bars ONLY
❗ Automotive (truck/SUV) applications
❗ Provides wiring for running, brake, and reverse functions
❗ Does NOT include turn signal functionality
❗ For RTL-S models with turn signals, you will also need:
   • Baja Designs 640130 (RTL-S Turn Signal Harness)
❗ Verify your light type before ordering

👉 This is critical — prevents incorrect installs and returns

Designed for RTL Rear Light Bars

• Purpose-built for Baja Designs RTL series
• Provides full functionality for rear safety lighting
• Ensures proper operation of all light outputs

👉 The correct harness for standard RTL setups

Full Rear Lighting Control

• Running light for constant visibility
• Brake light for stopping indication
• Reverse/cargo light for backing up and utility use

👉 Covers all core rear lighting functions

Extended Length for Rear Mounting

• Designed to reach rear bumpers or roll cages
• Ideal for trucks, SUVs, and overland builds
• Simplifies wiring across full vehicle length

👉 No need for custom extensions

Built for Off-Road Durability

• Heavy-duty wiring and sheathing
• Weather-resistant connectors
• Designed for vibration and harsh environments

Engineered to perform in extreme off-road conditions.

What’s Included

• Baja Designs RTL automotive wiring harness
• Relay and inline fuse
• Pre-terminated connectors
• Installation-ready wiring leads

Specifications

• Compatibility: RTL light bars
• Functions: Running / Brake / Reverse
• Application: Automotive (truck/SUV)
• Voltage: 12V system
• Connector Type: Weather-resistant connectors
• Harness Type: Rear lighting harness

Installation

Runs from front battery to rear light mounting location
Connects to vehicle lighting circuits
Includes relay and fuse protection
Professional installation recommended
Typical install time: ~45–90 minutes

Why Buy from Iron Ridge Offroad

✔ Fast Shipping
✔ Authorized Premium Brands
✔ Fast Processing
✔ Off-Road Experts You Can Trust

Complete your rear lighting setup with the Baja Designs Automotive RTL Wiring Harness (640127) built for reliable performance, full functionality, and clean installation on any off-road or overland vehicle.