25 ft 4-Way Flat Trailer Light Wiring Harness Kit – 4 Wire Bonded Cable
Part Number: 16977
This 25-foot trailer light wiring harness kit is designed to connect trailer lighting to a tow vehicle using a standard 4-way flat plug. The bonded, color-coded 4-wire cable helps simplify routing and identification of each circuit during installation.
R&P Knowledge Hub
A 4-way flat trailer wiring system supports the most common light functions:
running/tail lights, left turn/brake, right turn/brake, and ground.
Most trailer lighting issues come down to grounding — a clean, solid ground connection is required
for reliable operation. After installing any harness, always test each circuit with the tow vehicle
connected to confirm proper function.
Features
- 25 ft bonded 4-wire trailer light harness
- Standard 4-way flat connectors (male & female molded ends)
- Color-coded wires for easier identification and routing
- Supports tail/running, left turn/brake, right turn/brake, and ground circuits
- Common on utility, boat, cargo, and light-duty trailers
Specifications
| Specification | Detail |
| Part Number | 16977 |
| Connector Type | 4-Way Flat (molded ends) |
| Harness Length | 25 ft |
| Wire Type | Bonded 4-wire |
| Wire Gauge | 18 gauge |
| Functions Supported | Tail/Running • Left Turn/Brake • Right Turn/Brake • Ground |
| Color Coding | White = Ground • Brown = Tail/Running • Green = Right Turn/Brake • Yellow = Left Turn/Brake |
| Included | (1) 25 ft bonded 4-wire harness with molded 4-flat connectors (male & female) |
Verify wiring functions and test all lights after installation.