The 6-pin trailer plug (also called 6-way or 6-round) is commonly used on utility trailers, horse trailers, and small campers. Knowing the correct 6-wire trailer plug color code ensures proper lighting, brake, and power functions between your tow vehicle and trailer.
6-wire trailer plug color code
This guide covers the standard color codes, wiring layout, and tips to help you wire or troubleshoot a 6-way trailer connector.
🎯 Standard 6-Wire Trailer Plug Color Code & Functions
| Wire Color | Function | Terminal Label |
|---|---|---|
| White | Ground | G |
| Brown | Tail/running lights | T |
| Yellow | Left turn signal & brake light | LT |
| Green | Right turn signal & brake light | RT |
| Blue | Electric trailer brakes | S (Brake) |
| Red or Black | 12V Auxiliary power (battery) | A |
⚠️ Note: Color codes may vary slightly depending on manufacturer, but these are the most commonly accepted standards.
🔌 6-Pin Trailer Plug Terminal Diagram (Round Pin Style)
6-Pin Trailer Plug Terminal Diagram
📝 Pin position may vary by plug type (round, square, or blade), so always verify with a multimeter or test light before connecting.
🔍 Function Breakdown
⚪ White – Ground (G)
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Connects trailer frame to tow vehicle ground.
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Most critical wire for safety and operation.
🟤 Brown – Tail/Running Lights (T)
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Powers tail lights, license plate light, and side marker lights.
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Activated when headlights or parking lights are on.
🟡 Yellow – Left Turn Signal / Brake (LT)
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Combined wire for left turn signal and left brake light.
🟢 Green – Right Turn Signal / Brake (RT)
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Combined wire for right turn signal and right brake light.
🔵 Blue – Trailer Brakes (S)
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Supplies power from the brake controller to the trailer's electric brakes.
🔴 Red or ⚫ Black – 12V Power Supply (A)
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Used to charge trailer battery, power interior lights, or accessories.
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May require inline fuse or circuit breaker.
🧰 Tips for Wiring or Troubleshooting
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✅ Always test each pin on the vehicle side with a circuit tester.
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✅ Use dielectric grease to prevent corrosion in trailer connectors.
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✅ Label wires clearly when replacing connectors.
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✅ Check grounds—poor grounding causes many lighting issues.
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⚠️ Do not assume colors—always confirm wire function before connecting.
🚚 Applications of 6-Pin Trailer Connectors
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Horse trailers
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Enclosed cargo trailers
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Small campers (with brakes)
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Utility trailers with extra accessories
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Older RVs or farm trailers
For trailers without brakes, a 4-pin connector is usually sufficient. For more complex trailers (backup lights, reverse lockout, etc.), a 7-pin plug is recommended.
🔚 Conclusion
The 6-wire trailer plug color code helps ensure safe, functional connections between your vehicle and trailer. Always confirm both color and function before wiring, and test thoroughly to avoid brake, lighting, or charging issues on the road.
