HID Wiring Harness Explained


HID Accessory Relay Wiring Harness Explained!

A Wiring Harness' primary function is to provide power directly from the vehicles battery to the HID system.  This allows an HID system to operate independently of the vehicles electrical system and provides a more constant power source.


Whats in an Accessory Wiring Harness?

An Accessory Wiring Harness is also referred to as a Relay Wiring Harness as it utilizes a simple automotive relay in its design.  A Wiring Harness utilizes a 30amp fuse protected power wire that directly connects to your positive terminal on the battery.  An Automotive Relay is used to pull signal from a source (Headlight connector) that triggers power to be drawn from the battery.  There are two sets of cables meant to provide power to an HID ballast.  There are also two separate ground wire terminals that need to be connected to the chassis to complete the electrical circuit.



What does a Wiring Harness fix?

An Accessory Wiring Harness is capable of fixing a variety of power related HID lighting issues i.e. intermittent on/off, flickering, delayed start, HID low light output, and uneven brightness.


Problem: Delayed Start

An HID Ballast requires more power to ignite on startup than during normal usage.  This initial power surge can sometimes be problematic for vehicles with weaker electrical systems that cannot provide the power needed.  The vehicles stock headlight connectors are not capable of providing 7-8 amps per headlight and as a result, only one HID turns on when the switch is turned on.  After about 20 seconds when the ballasts power consumption drops to 3.2 amps, you can quickly turn the lights off then back on and voila, both HID lights turn on.  This scenario happens all the time and is the direct result of insufficient power.

Solution: An HID wiring harness with power supplied directly from the battery would eliminate this issue as it would be able to consume up to 30 amps through the batteries positive terminal to ignite both ballasts.


Problem: Flickering

An HID Ballast that is not getting sufficient power from a stock headlight connector will cycle on and off as it tries to ignite and power on.  This can also be a result of an inefficient ballast that is not able to convert the available power to properly ignite an HID system.

Solution: An HID wiring harness will provide the power necessary to ignite even an inefficient ballast for flicker free HID lighting.


Problem: Dim/Dark Light Output

When a ballast is underperforming, light output can appear more blue and dimmer than it should be.  This is a result of the ballast not converting enough power to ignite the bulb at its optimal range.   A bulb that is 4300K connected to a ballast with a weak power source, can look like an 8000K blue color with substantially lower light output.

Solution: An HID Wiring harness will be able to provide more power to the ballast allowing the system to operate at 100%.  This however is not a guaranteed solution as a poor quality ballast will not output sufficient power no matter how much is being inputted.


Problem: Uneven Brightness

My passenger side is brighter than my driver side!  Power in not always delivered in equal amounts to each headlight, and depending on your vehicles wiring configuration, can have a negative impact on lighting performance when installing HIDs.  If one headlight has less resistance to the power source i.e. less bends or curves in the wiring, length of wiring, fuse panels bridging connections etc, it will receive power first leaving less for the second headlight to consume.  In this scenario, one headlight will end up brighter than the other.

Solution: An HID wiring harness will provide equal amounts of power to each HID Ballast allowing for even and consistent brightness between both headlights.


To Buy or Not to Buy? An HID wiring harness for some vehicles is a safety and assurance item to prevent future problems, and for other vehicles is a necessary requirement to a successful HID installation.  We here at XenonSupply do our best to bundle packages together based on our research to make sure you have all the components necessary for a issue free installation.  Our general recommendation is to always use a harness where possible to help extend the life of your HID system.  Not only are you providing your HID ballasts with adequate power, you are protecting both your vehicle and HID system with the inline fuse that separates the systems. XenonSupply HID Accessory Relay Wiring Harness

As always, if you have additional questions please let us know.


XS Team

Tags: Tech Blog

Leave your comment

Comments have to be approved before showing up