GrimmSpeed Hella Horn Wiring Harness - 2015-21 WRX/STI, 2013-21 Subaru BRZ


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GrimmSpeed SKU: GRM040026

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Simple Problem. Simple Solution.

When it comes to wiring the Hella Horns mounted to your beautiful GrimmSpeed BroTie Bracket, we have you covered. Don’t stress yourself with trying to make a Hella horn harness from scratch when we offer a simple pre-assembled, OEM-quality harness that will allow you to plug and play in seconds. Our latest version of this harness has a custom-molded connector for an exact fit and is made longer to accommodate fitments for all 15+WRX/STI.

You’ll notice our harness does not incorporate the Hella-provided relay as standard. After some testing, we determined that the additional few dBs offered by wiring with a relay weren't worth the added headache and potential failure points of a more complex harness using the relay, inline fuse and additional wiring directly to your battery. Should your heart desire those last few ounces of dBs, our harness can be adapted for use with a more complex relay harness.


  • Automotive Grade 16ga Wire - Minimal resistance for maximum volume
  • Heat Shrink Terminals - Heat shrink, crimp-on terminals ensure a reliable connection
  • Protective Wire Sleeving - Clean black look, protects against abrasion and stress
  • Plug-n-Play with OEM Harness - Installs and uninstalls in seconds with our custom connector


  • 2015-21 Subaru WRX
  • 2015-21 Subaru STI
  • 2013-21 Subaru BRZ
  • 2013-16 Scion FRS
  • 2017-21 Toyota GT86