Universal Wiring Harness Kit 21 Circuit Long Wires - Easy GM Color

In this review the Auto Parts Prodigy Universal Wiring Harness Kit is evaluated for classic car builders who need a comprehensive, long-wire harness that simplifies wiring for hot rods and rat rods. The biggest reason to buy is the GM color coded wiring that makes identifying circuits faster during installation, and the kit includes 21 circuits useful for most vintage chassis conversions. It ships with a detailed instruction set that covers GM, Ford and Mopar variants, so builders who want a single harness to adapt to multiple platforms will find it appealing.

Key Features

• 21 circuit coverage: Includes horn, fan, dome light, hazard, radio, cigarette lighter, door locks and other core circuits so you rarely need extra wiring for a basic build.
• GM color coded wiring: Color coding follows GM conventions to speed identification and reduce guesswork when connecting multiple circuits.
• Extra long wires: Wires are intentionally long to accommodate stretched frames, custom mounts and unconventional engine bay layouts without splicing extensions.
• GXL 125 high temp wire: The cross linked polyethylene jacketed wire resists grease, oil, gas and acid for improved durability in an automotive environment.
• Platform instructions: The kit includes detailed instructions with specific pages for GM, Ford and Mopar to guide installers through common variations.

Who It's For

This harness is aimed at hobbyist builders and professional shops working on classic Chevy, Ford or Mopar based hot rods, rat rods and chassis swaps who want a single harness solution with long leads and broad circuit coverage. It fits best where OEM-style color coding will help speed a custom install and where protection from heat and fluids matters.

People who should look elsewhere include restorers needing an exact factory OEM reproduction harness with original connectors, and installers who require an ultra-simplified plug-and-play kit for modern vehicles with integrated computer modules.

Pros & Cons

Pros

• Comprehensive 21 circuit list covers most needs for classic car builds without hunting for extra wires.
• GM color coded wires make tracing and routing easier for those familiar with GM wiring conventions.
• Extra long runs and GXL 125 jacketed wire add flexibility and durability in custom engine bays.
• Includes instructions tailored to GM, Ford and Mopar to reduce installation guesswork.

Cons

• Wire labeling receives mixed feedback, so some installers may spend extra time confirming circuit ends during hookup.
• Instructions are useful but some customers report the schematic can be hard to follow for complex swaps.

Specifications

Brand	Auto Parts Prodigy
Circuits included	21 circuit harness (horn, fan, dome light, hazard, radio, etc.)
Wire jacket	GXL 125 high temp cross linked polyethylene
Color coding	GM color coded for easier identification
Wire length	Extra long wires to accommodate custom builds
Documentation	Instructions with specific pages for GM, Ford and Mopar

Our Verdict

The Universal Wiring Harness Kit is a practical choice for classic car builders who need a robust, long-reach 21 circuit harness that simplifies wiring with GM color coding and durable GXL 125 wire. It offers strong value for most hot rod and rat rod projects, though installers should be prepared to verify some labels and consult the schematic for complex swaps.

Frequently Asked Questions

Will this harness work for GM, Ford and Mopar cars?
The kit includes instructions and pages specific to GM, Ford and Mopar, making it adaptable across those platforms.

Are the wires durable for engine bay use?
Yes, wires use GXL 125 high temp jacketed insulation that resists grease, oil, gas and acid for automotive environments.

Is professional installation required?
Professional installation is recommended for complex swaps, though experienced hobbyists will find the color coding and instructions helpful.