GrimmSpeed Hella Supertone Horn Wiring Harness - 2015+ WRX / STI / 2013+ BRZ

GrimmSpeed Hella Supertone Horn Wiring Harness - 2015+ WRX / STI / 2013+ BRZ



SKU: 040015

13 left in stock. In Stock

This plug and play harness allows for quick wiring of Hella horns.

NOTE: FR-S / 86 / BRZ vehicles may require shaving down the locator pin on the connector for proper fit. This is a quick modification.



When it comes to wiring the Hella Horns that are mounted to your beautiful GrimmSpeed BroTie, we have you covered. 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 automotive relay, inline fuse and additional wiring directly to your battery. Fully pre-assembled, our simple harness will allow you to plug and play in seconds. Should your heart desire those last few ounces of ear-piercing goodness, our harness can also be adapted for use with a more complex relay harness. Diagrams for that configuration are included in our installation guide below.


  • 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

This Part Fits

  • 2015-2020 STI GrimmSpeed Hella Supertone Horn Wiring Harness
  • 2015-2020 WRX GrimmSpeed Hella Supertone Horn Wiring Harness


Additional Information

Installation Instructions Download here.
Additional Warranty Information No

2 customer reviews

Average rating
(based on 2 reviews)
Ease of Installation
Fit / Quality
Overall Satisfaction
  1. Clean and easy.

    By Kevin October 01, 2017

    This is by far the easiest way to wire up the Hella horn. I would also recommend unplugging the horn by the right wheel so as not to overload the amps.

  2. Perfect!

    By Quin April 26, 2017

    Excellent product. Very easy to install. Clean and neat.

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