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Plug and Play Power for Aftermarket Horns
The GrimmSpeed Hella Horn Wiring Harness makes it simple to add louder aftermarket Hella horns to a 2015 and newer Subaru WRX or STI without cutting into the factory wiring. GRMGRM040026 uses automotive grade 16 gauge wire to minimize resistance and deliver maximum volume to the new horns, while heat shrink crimp on terminals keep every connection reliable over time. A protective wire sleeving gives GRMGRM040026 a clean black look while guarding against abrasion and vibration related stress. Designed to plug directly into the OEM harness, this kit installs and uninstalls in seconds, making it an easy companion to a set of Hella horns and the GrimmSpeed BroTie mounting bracket.
Key Features
- Automotive grade 16 gauge wire for minimal resistance and maximum volume
- Heat shrink, crimp on terminals for a reliable connection
- Protective wire sleeving for a clean look and added durability
- Plug and play design that installs and uninstalls in seconds
- Compatible with the OEM horn harness connector
- Can be adapted for use with a more complex relay harness if desired
Fitment
| Year | Make | Model |
|---|---|---|
| 2015-2021 | Subaru | WRX |
| 2015-2021 | Subaru | WRX STI |
Specifications
| Detail | Value |
|---|---|
| SKU | GRMGRM040026 |
| Manufacturer Part Number | 040026 |
| Wire Gauge | 16ga Automotive Grade |
| Terminal Type | Heat Shrink Crimp On |
| Fitment | 2015-2021 Subaru WRX and STI |
| UPC | Not published by manufacturer |
What's Included
- 1 GrimmSpeed Hella Horn Wiring Harness (GRMGRM040026)
About GrimmSpeed
GrimmSpeed is a Minnesota based performance manufacturer known for practical, well engineered Subaru specific upgrades. GRMGRM040026 continues that approach by taking a common upgrade, aftermarket horns, and making the wiring simple and reliable.
FAQ
What is the 040026?The 040026 is the GrimmSpeed Hella Horn Wiring Harness designed for 2015 and newer Subaru WRX and STI models.
Which vehicles does GRMGRM040026 fit?It fits 2015 to 2021 Subaru WRX and 2015 to 2021 Subaru WRX STI models.
Does GRMGRM040026 include a relay?No, GrimmSpeed testing found the added volume from a relay was not worth the extra complexity, so the standard harness does not include one.
Can this harness be adapted to add a relay later?Yes, GRMGRM040026 can be adapted for use with a more complex relay based harness if desired.
Does this harness require cutting the factory wiring?No, it plugs directly into the OEM horn harness connector for a plug and play installation.
What gauge wire is used in GRMGRM040026?It uses automotive grade 16 gauge wire to minimize resistance and maximize volume.
Is a mounting bracket included with this harness?No, this listing is for the wiring harness only. A bracket such as the GrimmSpeed BroTie is sold separately.
How long does installation take?Most installers can connect the harness in a few minutes once the horns and bracket are in place.
Install Instructions
- Disconnect the factory horn connector from the OEM harness.
- Mount the aftermarket Hella horns to a bracket such as the GrimmSpeed BroTie.
- Connect the female terminals of GRMGRM040026 to the spade connectors on each horn.
- Plug the male terminal end into the factory OEM harness connector.
- Route and secure the wiring away from moving parts and sharp edges.
- Test the horns before reinstalling any bumper or trim panels.
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