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Diode Dynamics Heavy-Duty HID Relay Harness (DD4027)


10% of profits donated to Sierra Club and 1% of all sales donated to Stripe Climate Change initiative.

Diode Dynamics Heavy-Duty HID Relay Harness Single

On backorder, place an order to reserve

GTIN: 691026115177 SKU: DD4027 Category:

Prevent flickering. In some cases, you may experience flickering after installing HIDs in your vehicle. This is due to the fact that the factory wiring doesn’t draw enough power to ignite the HID bulbs. The Heavy-Duty HID Relay will power your HIDs directly from the battery, instead of the factory wiring, to prevent any flickering, while still retaining factory function. This relay has been designed with a fully-sealed, waterproof relay, with flyback diode, and has a built-in capacitor for input power smoothing.

Plug and play. The HID Relay Harness was designed for use with all Diode Dynamics HID Conversion Kits. Both input wires are one meter long, and the two output wires are one meter and two meters to reach both sides of the vehicle. The OEM-style connectors allow for easy, plug-and-play connection to the ballasts and HID bulb. Only one relay harness is needed to power both sides of the vehicle.

Experience. After over a decade in business, Diode Dynamics is the most trusted name in automotive LED lighting. Unlike every other LED distributor, we assemble and engineer products ourselves in the United States, for high quality and fast time-to-market of the newest and brightest LED technologies. We pride ourselves in offering only quality LED products, that will exceed your expectations.

  • Prevents flickering after installing HID bulbs
  • Powers HID bulbs directly from the battery
  • Compatible with all Diode Dynamics HID Conversion Kits
  • Fully-sealed, waterproof design

What’s Included In the Box:

  • One (1) Heavy-Duty HID Relay Harness to power both sides of the vehicle
  • Quantity: One (1)
  • Warranty: 3 year warranty
  • Return Policy: 30-day Return with no restocking fee
  • 100 percent Satisfaction Guarantee


  • This product was designed for use with all 35W Diode Dynamics HID Conversion Kits


  • Operating Voltage: 9-16V
  • Operating Temperature: -40C to 85C (-40F to 185F)
  • Driver Features: Waterproof
  • Weight (lb): 1.0000


Diode Dynamics

Diode Dynamics is our top manufacturer of automotive LED lighting products.

By directly manufacturing their products in St. Louis, Missouri, they are able to carefully control quality, while bringing unique items to market much faster than their competition. They back their products with an industry-leading no-hassle warranty, and the best service and support experience possible. From replacement LED bulbs, full LED assemblies, multicolor accents, or unique lighting control modules, Diode Dynamics is the leader in LED lighting.
Weight 1 lbs
Dimensions 1 × 1 × 1 in
WarningWARNING: This product may expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to