View Full Version : Headlight Q&A for Idiots

09-27-2010, 06:12 PM
So I'm preparing to do a 55w 6000k (or 5000k, still not sure) HID kit install on my front headlights (projectors, ballasts, dunno what they're called) and just wanted to make sure Im doing everything right. I've read up on the DIY, searched and found that DDM is probably the best option for the price.

Anyways, I'm just a little confused with the technical aspect behind HID's. Do HID's provide an alternate "energy" source, so to speak, that alters the power output of the already stock H7 bulb? Or does it just replace the entire bulb with a new "HID" one. On the picture there are tiny bulbs surrounded by plastic covers, would this be the ballast? I like to know exactly what it is that I'm doing before I start messing with my lights.


09-27-2010, 06:36 PM
Those bulbs you see you will get with the kit and they replace your stock bulb. That plastic cover is just a cover to protect the actual bulb while in transport. The black bricks you see there are the actual ballasts that you will have to connect to the power for your headlights. It's actually a fairly simple, straightforward install, one of the first things I did + new headlight housings.

Edit: Get the 6000K with the 55 watt, it'll look closer to 5000k, I have that same setup

09-27-2010, 06:37 PM
the ballast is the piece that says ddm and yes the bulb is entirely different. they are the bulbs with the covers on them in your picture.

EuroTrash A4 NY
09-27-2010, 06:37 PM
The DDM kit is a plug and play kit, with a little extra modifications. You will be removing your headlight as well as the low beam bulbs. The bulbs in the plastic covers will be your new bulb, installed in the same position your halogen bulbs were, with the plastic cover removed.

Basically, you will install the bulb into the factory position, plug the bulb into that box that says DDM on it (which is the ballast), then plug the ballast into the headlight, and finally plug the headlight into your car as normal.

You will need to cut a hole in the back of your headlight housing and slide the bulb through that hole. The kit comes will a waterproof seal but it is best to seal it will a bit of silicone to make sure it is water tight. The DDM kit comes with very helpfull instructions, and you should have little trouble installing them.

09-28-2010, 11:04 AM
If you want to know how HIDs work (or most things), I advise you to search Google/Wikipedia/etc. Here's a simple explanation. Typical halogen bulbs (H7,H4, etc) that most cars come with work by running a current through a filament that makes it get so hot it glows (very brightly). This is also how incandescent bulbs (normal household bulbs) work, withe some slight differences.

HID bulbs work by creating an arc (continuous spark) between to points inside the bulb to provide light. They are also called Xenon bulbs because that's the gas inside the bulb. This spark requires very high voltages (70,000-80,000V or so), but your car only puts out about 14. Those black boxes are the "ballasts" that, among other things, create this high voltage.

The light from HID bulbs is much more intense but also covers a much narrower spectrum. Get close to 5300K color temperature if you want to see well. People like other colors, but they don't help you see as much, except for some cases like yellow light in rain/fog.