JY PERFORMANCE Universal 21-Circuit Wiring Harness Kit — 17 Fuses, Labeled Copper-Core for Classic & Custom Cars

The JY PERFORMANCE Universal 21-circuit wiring harness kit with 17 fuses is a complete, labeled harness bundle designed to replace or retrofit electrical systems on classic and custom vehicles.

This universal wiring harness provides a tidy, OEM-style solution for restoring or upgrading automotive electrical systems. Built from copper-core conductors and color-coded, labeled leads, the kit groups 21 individual circuits and includes 17 fuse locations to protect key loads. It was developed to work across many makes and models—GM, Ford, Chrysler and more—so fabricators, restorers and hot-rod builders can simplify wiring work without starting from scratch.

How does this 21-circuit harness simplify a restoration or custom build?

Instead of splicing dozens of individual wires, this harness delivers pre-assembled circuits with clear labeling and standardized colors, reducing installation time and mistakes. The grouped layout mirrors common vehicle functions, making it easier to map old wiring or plan new routing. Labeled intervals every five inches help you locate and identify lines quickly.

• Pre-labeled leads and color coding for fast identification
• 21 distinct circuits covering lights, gauges, accessories and more
• 17 fuse positions to protect multiple electrical loads
• Designed for universal fit across classic and modern vehicles

Which circuits and accessories are included in the kit?

The harness covers the typical vehicle circuits you’ll need for a streetable build or restoration. It includes power and switched feeds for lighting, ignition, convenience items and key drivetrain sensors, so you can support both original-style equipment and common aftermarket accessories. This breadth reduces the need for additional custom wiring.

• Headlights, tail/brake lights, turn signals and backup lights
• Ignition coil, gauges, fuel pump and electric fan circuits
• Radio, cigarette lighter, dome light, door locks, power windows
• Wipers, choke, cruise control and hazard systems

What materials and safety features are built into the harness?

The harness uses copper-core wire for reliable conductivity and flexibility during routing and installation. Each circuit terminates with standardized connectors or labeled ends, and circuits are grouped and protected via the 17 fuse panel to limit damage from overloads. The wiring jacket and connectors are selected for corrosion resistance typical of automotive environments.

• Copper conductor cores for high electrical conductivity and ductility
• Clear, corrosion-resistant connectors and durable insulation
• 17 fuse slots to isolate and protect individual loads
• Labels every five inches for easy identification and troubleshooting

How should I plan installation and compatibility checks?

Although labeled as universal, this kit requires planning to match vehicle-specific connectors and mounting points. Review your vehicle’s wiring diagram, identify required circuits, and trim or adapt leads as needed. If you’re unsure about routing, grounding or fuse placement, consult a professional installer to ensure safe operation.

• Compare included circuits to your vehicle’s wiring needs before installation
• Trim, adapt or re-terminate leads to match factory connectors when necessary
• Confirm ground points and fuse allocation for critical systems
• Seek professional help for complex electrical or modern ECU integrations

Who is this for? The JY PERFORMANCE Universal 21-circuit wiring harness kit is for automotive restorers, hot-rod builders, custom shops and DIY mechanics who want a comprehensive, labeled wiring solution that speeds installation and reduces wiring errors. It’s especially useful for classic car projects, rat-rods and custom builds where a near-complete harness can replace brittle factory wiring, but installers should be comfortable adapting universal leads to vehicle-specific connectors and routing. When in doubt about modern ECU or safety system integration, use a qualified auto electrician to finalize the installation.