Air and Fuel› Intake Manifolds and Components
GrimmSpeed
GrimmSpeed 02-14 Subaru WRX/STI Hella Horn Wiring Harness
SKU: G00B 040005
Easy — 1–2 hours
Description
GrimmSpeed opted not to include a relay by default, as testing indicated the minimal dB gain wasn't worth the added complexity and potential failure points. However, the harness can be adapted for use with a relay system if desired.
Fitment
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Specifications
| Brand | GrimmSpeed |
| Part Number | G00B 040005 |
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Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.
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