HD Relay: H11

The Morimoto HD Relay Harness H40 is engineered to provide a clean, stable power supply directly from your vehicle's battery to your HID ballasts. By bypassing the limitations of your factory headlight wiring, the H40 eliminates common HID issues such as flickering, inconsistent startup, and voltage fluctuations, ensuring reliable performance every time you drive.

Factory headlight circuits were designed to power halogen bulbs—not the higher startup demands of HID ballasts. The Morimoto H40 solves this problem by supplying consistent battery voltage for maximum HID performance and reliability.

Why Use a Relay Harness?

A relay harness is one of the most important components of any HID conversion. Even premium HID bulbs and ballasts cannot perform properly if they aren't receiving stable power. The Morimoto H40 protects your investment by improving ballast startup, maintaining consistent light output, and reducing the electrical load on your factory headlight circuit.

True Plug-and-Play Installation

Designed for fast and straightforward installation, the Morimoto H40 requires no cutting or splicing. Its universal layout and generous wire lengths make it compatible with most cars, trucks, SUVs, and off-road vehicles.

Installation is simple:

• Connect the harness directly to the battery
• Plug into your factory headlight connector
• Connect your HID ballasts
• Secure the relays and wiring

The result is a clean, reliable installation with OEM-quality performance.

Universal Compatibility

The Morimoto H40 uses industry-standard ballast connectors and is compatible with nearly all aftermarket HID lighting systems.

Compatible with:

• HID Low Beam conversions
• HID High Beam conversions
• HID Fog Light conversions

Important: Vehicles equipped with CANBUS electrical systems or pulsed Daytime Running Lights (DRLs) may require a Morimoto CANBUS or Mopar-specific relay harness for proper operation.

Dual Relay Fail-Safe Design

Unlike many inexpensive relay harnesses that rely on a single relay to power both headlights, the Morimoto H40 features dual independent 40A sealed relays, providing one dedicated relay for each headlight. This fail-safe design ensures continued operation of one headlight should a relay ever fail.

Each relay includes:

• Fully sealed weather-resistant housing
• Silicone weather seals
• Integrated flyback diode for back-EMF protection
• Weatherproof connectors throughout the harness

Built to handle rain, snow, road salt, moisture, and extreme temperatures, the H40 is engineered for dependable long-term performance.

Premium OEM-Grade Construction

Morimoto is known for manufacturing high-quality automotive lighting products, and the H40 Relay Harness is no exception.

Premium construction features include:

• Heavy-duty automotive-grade wiring
• Abrasion-resistant Techflex braided sleeving
• OEM-style sealed relay housings
• Stainless-steel relay mounting bracket
• Weatherproof electrical connectors

The finished installation looks clean and factory-installed while providing years of dependable service.

Features

• Supplies stable battery voltage directly to HID ballasts
• Eliminates flickering and inconsistent HID performance
• Universal plug-and-play installation
• No cutting or splicing required
• Compatible with most aftermarket HID systems
• Suitable for low beams, high beams, and fog lights
• Dual independent sealed 40A relays
• Flyback diode protection for enhanced electrical reliability
• Premium weatherproof construction
• OEM-quality fit and finish

Package Includes

• 1 × Morimoto HD Relay Harness H40
• Complete plug-and-play HID relay harness for one vehicle

Whether you're installing a new HID conversion kit or upgrading an existing system, the Morimoto HD Relay Harness H40 delivers the stable power, premium construction, and long-lasting reliability needed for professional-quality HID performance in virtually any vehicle.