Grimmspeed GRM040026 Hella Horn Plug-and-Play Wiring Harness

The GrimmSpeed GRM040026 Hella Horn Wiring Harness is a fully pre-assembled, OEM-quality wiring harness designed to make upgrading to Hella horns a clean and hassle-free experience. Built with automotive-grade components and a custom-molded connector, this harness plugs directly into the factory horn wiring with no cutting, splicing, or custom fabrication required.

GrimmSpeed engineered this harness without the Hella-provided relay by design. After extensive testing, they determined that the marginal volume increase from a relay-based setup was not worth the added wiring complexity or potential failure points. The result is a simpler, more reliable harness that delivers excellent horn output right out of the box. For those who still want relay functionality, this harness can be adapted for use with a more complex relay harness.

The latest version features an extended length to properly reach horn mounting locations across all supported fitments, and pairs perfectly with the GrimmSpeed BroTie horn bracket.

Key Features:

• Automotive-Grade 16ga Wire — Low resistance construction maximizes horn output volume
• Heat-Shrink Crimp Terminals — Sealed, crimped connections ensure long-term reliability and corrosion resistance
• Protective Wire Sleeving — Clean black finish protects against abrasion, heat, and stress
• Custom-Molded OEM-Fit Connector — Plugs directly into factory horn wiring; installs and uninstalls in seconds
• Relay-Free Design — Simplified, dependable setup with fewer failure points
• Relay-Compatible — Can be adapted for use with an external relay harness if desired
• Lifetime Warranty — GrimmSpeed warrants this product against manufacturing defects for the lifetime of the product

What's Included:

• 1x GrimmSpeed Hella Horn Wiring Harness

Supersedes Part Number: 040015