Hi All,

I'm in the market for a HID kit for my IS350 (headlights and foglights). I can get the HID kit from hidynamic.com for $250 each but they're the ones that are powered from the stock wiring harness. I've heard that it is better if the HIDs get the power directly from the battery since the HIDs require a lot of power while starting up. So what kits draw power directly from the battery?

Thanks,
TJ

 

Actually MOST are not powered by your stock wiring. They use your existing wiring simply for the switched power (on-off).

You should still run the main power wires from the battery to the relays. The relays pull the power needed from your battery directly and uses your existing wiring harness only to turn the system on and off.

Make sense?

Even if you do get a system that uses your existing wiring harness all you have to do is go to radioshack and pick up 2 SPST relays and wire the main power from your battery and the switched power from your existing harness. easy.

 

I understand the whole relay thing I just never realized I could do it myself. Does anyone have a diagram of how the relay is hooked up? I understand stuff better visually. If it's that easy then I'll just buy the kit and setup the relays myself.

 

here yuh go
Relay Info

 

thank you! that helps a lot!

 

actually most of the OLD kits (back in 2001, 2002) they draw powers directly from the harness. all my previous kits were like that actually, and i had two relays, one for each side.

it's towards end of 2002 that kits started to draw juice from the battery directly, and also i *think* there is only one relay instead of two. getting power from battery is better option, imho more stable, though installation wont' be as clean in most cases (coz' of the extra wires.

 

I agree with it probably being more stable. I've learned from previous car just do things right the first time. And the right way usually means money and time.

 

Im sorry but you guys obviously dont know what your talking about. Hid kits USE FACTORY WIRING! They draw far less than a halogen bulb. the only time they draw a lot is when they first start up. In case you dident realize this, your factory headlight wiring goes to relays which draw power from the battery, so i dont understand why you are going through all this trouble??? the bulb connects to the ballast and then from the ballast to the factory headlight wiring which goes to the relays then to the battery and your headlight switch. You guys are talking about all this relay stuff and your wasting your time, the car already has relays for the headlights, what your doing now is absolutly pointless! Unless you want to upgrade the factory wiring to a bigger size there is no sense in doing what you are saying....

 

bumpinlex - the problem with going with just the OEM wiring harness is that upon startup, there is not enough voltage produced through the actual headlight system to ignite the aftermarket HIDs. therefore, in order to compensate for this problem, there are HID replacement kits out there that offer a seperate relay wiring harness which draws directly from the battery instead of going through the car's actual system.

 

bumpin, i am not even going to spend much time here, but why don't you try to go out, get a hid kits, put it on your car, WITHOUT using any extra relay from the stock harness and the ballast? let's see what happens.

most people know that hid draws less avg current than halogen, but you said the reason of huge current spike when igniting the bulb. that's why people need to upgrade fuse to 20amp otherwise the stock 15amp fuse (for example on the 2gs) will blow. so why not just tap it off battery with clearly sufficient juice?

oh and btw, you might want to keep your attitude to yourself. if you have ponits, make them but stay that way. we don't need your kind of attitude here, got that?

 

Whatever you do dont listen to this. Run the power off the battery through relays. Thats how the HID kits Ive had and seen do it, plain and simple

 

if you just want to buy the kit...here are some good ones... and i agree with everyone here, do the extra wiring with the relays. I'm actually doing the same thing this weekend and its my first time doing it . After extensive searches and alot of reading, with the relays is the way to go. Plus one of my friends installs HID's at his shop and he told me the exact same thing.

ooh and i know several people who have bought their kits from hidynamic.com

http://www.eautoworks.com/html/ape-L...ty~Harness.htm

 

XenonDepot sells the relay by itself too. I'm debating if I should get the XenonDepot kit or get the hidynamic kit and buy the relays from XenonDepot.

 

Which harness kit is better, the one from Xenondepot or the one from hidynamic? Do either one of them come with dual relays?

 

Running right off the stock wiring WILL work on our cars. Assuming that the ballast circuitry is "relatively advanced". Many of the cheapie ballasts will only ignite and stay lit with a stable power source and they take much more power to ignite than the OEM units. The OEM Koito ballast will have no problem running off the stock harness. It has a very wide range of voltage acceptance on igntion and does not have as much of a power surge. However, it is still much much better to use a relay.

The ballast pulls several times of the rated 35W on ignition. In a poorly designed ballast with insufficient capacitors, this wattage can easily spike up in the hundreds. Even though the ignition is only a few seconds, the stock wiring will heat up significantly. Depending on how thin the wiring is, the insulation may even be melted slowly. Damage will not occur immediately, but will show up over time. The constant ignition cycles will deteriorate the insulation or the wire connections and possibly cause it to fail over time. This is why you use a relay. Its much cheaper and easier to replace a $3 relay than to troubleshoot the stock wiring harness if something goes wrong.

Running a relay does not have to be ugly mess of wires. For my setup, everything (ballast, wiring, relays, etc) is tucked under the passenger side headlight and stuck against a part of the chassis with 3M industrial double sided tape (5lb stick per sq inch!). The ground wire is hooked up to a chassis bolt and only one 10ga wire runs to the battery. For the power on the driver side, the wire is run in front of the radiator (tucked and zip tied). Granted this process takes a LONG time and is a ton of work, but the results are worthwhile. If you are experienced in electrical wiring, this will be a piece of cake. For those who aren't so experienced, it will be a good liitle weekend project

If someone was to take a peek under my hood, it looks 100% OEM.