What do hid relays do

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. This is a result of the ballast not converting enough power to ignite the bulb at its optimal range. A bulb that is K connected to a ballast with a weak power source, can look like an K blue color with substantially lower light output. This however is not a guaranteed solution as a poor quality ballast which 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. In this scenario, one headlight could end up being brighter than the other, or powering up to full brightness faster than the other. Solution: An HID wiring relay 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.

My general recommendation is to always use a harness where possible to help extend the life of your HID system, avoid unnecessary headaches, or to boost the output of your halogen light bulbs. There are also two separate ground wire terminals that need to be connected to the chassis to complete the electrical circuit. Any lighting system can benefit from increased current capacity in the wiring.

What does a Wiring Harness fix? 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. A general recommendation is to always use a harness where possible to help extend the life of your HID system, avoid unnecessary headaches, or to boost the output of your halogen light bulbs.

I tried to ignite my 35 watt ballasts without a relay harness and it wouldn't do it. It didn't blow any fuses but the ballast wouldn't light. Trs told me that the 35 watt ballasts can draw around 8 amps at start up. My stock fuses are 10 amps per light. And another reason that is a guess, the relay provides a cleaner, more direct power since it's coming right from the battery. Thats true, I must've completely overlooked the the surge they need to ignite.

I knew they needed "more" power at startup, but didn't think of the surge. Boy I feel dumb now, lol. It's not just about the wattage. With HID' ballasts it's more about the startup current draw. My car, like yours had a fuse for each individual headlight rated 10A.

My Gen III Matsus popped that fuse every single time, so I went for a relay instead of just throwing in a larger fuse which could present an issue if the stock harness was not rated for a higher amperage. It's true that often times car are "over-engineered" and the likelihood that the stock wiring will fry with newer cars is slim but a relay circumvents that issue altogether. I don't know if you know what happens when you put a higher load on a harness which it was not designed to, but depending on the amperage the cable can either get warm or flat out burn the insulation from the heat generated.

Originally posted by HK45 View Post. I run Denso ballasts on stock wiring, and for those who have owned late 90's Toyota's, you'll know how thin the wiring used is. Works just fine, fires without fail. Haven't had a single issue. The current draw isn't really higher than a halogen bulb due to the lower wattage and higher voltage, and the stock wiring is often already relayed with a fuse to the battery.

That's what the headlight relay is for.