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Discussion Starter · #1 ·
Im installing my 6000K on saturday but it just keeps puzzling me how the lights work with the relay harness if only the drivers side factory harness is the only one that connects to the kit? Like what happens to the harness on the passenger side? I think i am going to not install the relay harness but i am still curious about this in case i have problems and need to install it.
 

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Don't use the Relay harness on your Civic, it is not necessary. Just plug the HID kit into your existing wiring.

To answer your question about the relay harness and what happens to the OEM harness on the passenger side.

The way a relay harness works is that the power supply for the lamps comes directly from the battery. The relay is operated by the drivers side (or the passengers side for that matter) low beam lamp circuit. This voltage makes the relay close, and this lets the power from the battery energize the HID lamps. Because the relay harness uses the lamp supply line to power the relay and not the HID ballast, only one lamp line is needed, and the other is redundant.

This issue with a relay harness is that it is not adequately fused for safety. It only has one high amperage fuse for both lamps. This means that if you are driving at night and have a problem with one ballast that causes the fuse to open, you loose both low beam lamps. As you can imagine, this is not good.

The OEM harness on the other hand, has low amperage fuses for each lamp leg, and an higher amperage fuse for the entire low beam circuit. This protects each lamp from being turned off, if the other lamp has a problem, but also has a larger fuse if there is a catastrophic problem on both lamps (like a collision that shorts out both lamp power lines to ground). The OEM lighting circuit also has the right gauge wire for the HID retrofit kits.
 

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Discussion Starter · #4 ·
Man OE you know alot about these things lol. Ya I jsut wanted to clear everything up because it seems so weird that you only hook up one factory harness. Ya im not going to use it and it should be a faster install then too. :) Thanks
 

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i've had my klight kit for about 8 months now, didn't use the relay and it is working fine. But i've read up on some thread and people have been saying to use it, an "insurance" and now i've read what OE is saying and not sure anymore...
 

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relay harness power is managed by the relay itself. If there IS something going on, the juice is extracted from the battery rather than pop the fuse under each circuit thus you will be protected but if it overexceeds the amperage, of course both fuses on each circuit going to the ballast will pop then if more is used then the main fuse going to the + side of the battery will pop.
In other words, the insurance you get is from both the fuses and relay itself.
Here's a little example::sadwavy:
 

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is the oem harness in the car already or is this something additional you need to buy? if it is in the car is it plug and play with the ballasts?

Yes, the car's wiring for the lighting circuit is what I am calling the "OEM harness", and is already installed in the car. This is the essence of PnP.

You Civic is PnP with the Klight kit.
 
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