HD Relay: H7

1 Review

Brand: Morimoto




PART #: 1 x H30

Easy Return


Introducing the HD Relay Harness – the ultimate solution for flawless HID lighting upgrades! Say goodbye to flickering headlights and compromised performance. Designed to deliver a steady voltage directly from your car battery, this harness ensures stable power supply to HID ballasts. Don't cut corners on wiring – the HD Relay Harness guarantees top-notch quality and reliability, preserving the lifespan of your headlights. With easy Plug n Play installation, extended wire lengths for all vehicle types, and compatibility with 99% of ballasts, it's a no-brainer upgrade. Plus, its fail-safe design featuring individual relays for each side guarantees you won't be left in the dark. Experience premium performance and a sleek under-the-hood look with abrasion-resistant sleeving and polished stainless components. Elevate your lighting game today with the HD Relay Harness!


  • Steady Performance: The HD Relay Harness ensures consistent HID lighting, eliminating flickering.
  • Easy Setup: With plug-and-play design, it's perfect for enthusiasts and beginners.
  • Fail-Safe: Individual relays guarantee continued illumination even if one side has an issue.
  • Universal Compatibility: Works with various vehicles and lights for seamless integration.
  • Durable & Sleek: Weather-resistant protection and OEM-grade design elevate your lighting setup.


  • Harness: 1x HD Relay Harness

  • Input Adapter: 1x H7 Harness Input Adapter

  • Note: One harness controls both headlights


This Morimoto product includes a 2 Year limited warranty, serviced and supported by the Morimoto team in Atlanta, GA. This warranty does not cover modifications, alterations, or misuse. For additional information, Click Here.


  • Input: 1x H7 Male

  • Output: 2x 9006 Female

  • 12V Power: 1x Nickel-Plated Ring Terminal

  • Fuse: Inline 20A



  • HID SYSTEMS: Low Beams, High Beams, or Fog Lights

  • BI-XENON PROJECTORS?: You'll need High Beam Splitters

  • PWM PULSING SIGNAL?: You'll need a Capacitor Link

  • CANBUS SYSTEM?: Use Standalone Canbus or the Mopar Spec harnesses


Reality Check: Customers often ask, Do I really need a harness? Yes! A relay harness is designed to deliver steady voltage to your HID ballasts directly from the car battery. Nobody likes a flickering headlight, so why risk it? Factory headlight outputs are really only designed to power a halogen light bub, not an HID ballast.

Don't Skimp: As one of the most important parts in any HID lighting upgrade; don't skimp out when it comes to your wiring. It doesn't matter how good your ballasts are. how good your bulbs are. If your harness is a piece of crap: when it gives out your headlights are gonezo. The Morimoto HD Relay harness is easily worth the premium price compared to cheaper alternatives.

Plug n Play: The layout of the harness makes it easy to install. With just a few simple connections, even your mom could set this thing up! Wire lengths are long enough to be used in everything from compact cars to SUVs and it's designed to be 100% plug and play (no cutting or splicing needed). Its connections are explained in this video.

Compatible: The HD relay can be used for low beams, high beams, or fog lights on most vehicles. The harness uses industry-standard outputs for compatibility with 99% of ballasts out there, and all of the ones we offer here at TRS. Note, if your vehicle has a can-bus system or a finicky pulsed headlight circuit - check out our Standalone Canbus or the Mopar Spec harnesses.

Fail-Safe: Unlike most generic harnesses out there that rely on a single low-quality relay to power both headlights, the Morimoto Harness utilizes one relay per side- so if one did happen fail, you wouldn't be left completely in the dark. Each 40A relay is completely sealed against the elements using ribbed silicone upper and lower seals, and has an flywheel diode for back-EMF protection. Every other connection harness-wide is sealed with the proper silicone grommets. Live somewhere with weather that regularly sucks? No problem.

OEM Grade: Aside from being ahead of the game from a technical standpoint, the HD relay is also a work of art. With it's wiring protected by abrasion resistant Techflex mesh sleeving and OEM-style relay cubes held together by a laser engraved mounting bracket that's been artfully anodized with a titanium gray finish - the HD relay will look factory fresh under the hood!

Ratings & Reviews

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Pros: Very good quality. I had a problem when I quickly turned off / on my HIDs (CNLight bulbs and Hylux 2a88 ballasts), the one on the right remained off. It is now a problem solved, I even have the impression that they reach their maximum intensity faster.

Less: The shipping costs to France are almost worth the price of the product (20 €).

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