SKU: HLY558-403
UPC: 090127666449
MPN: 558-403
The HOLLEY J3 Connector & Harness (part number 558-403) is a dedicated wiring solution designed for modern fuel injection and engine management systems. This product is ideal for those building or upgrading a fuel-injected engine, whether swapping a modern powerplant into a classic chassis or fine-tuning an existing EFI setup.
This harness provides a critical electrical bridge between your Holley ECU and fuel injectors, employing precision-molded connectors and color-coded wiring to ensure reliable signal transmission and power delivery. The connector configuration is optimized for Holley's EFI systems, managing voltage regulation and ground returns with minimal signal loss, which is essential for consistent fuel atomization and combustion timing.
Engine builders, restoration shops, and fuel injection retrofit specialists rely on the J3 Connector & Harness for installation or troubleshooting. The harness is constructed with automotive-grade insulation rated for underhood heat cycles, vibration resistance, and corrosion protection, ensuring longevity in high-performance environments.
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