This section shares the solution to an issue I was having with my HID kit. The problem was, when I would turn the lights on, my parking brake and ABS lights on the gauge cluster would come on. Half the time they would turn off after about 5 seconds, the other half of the time they would stay on until I shut off the engine. I couldn’t find anything actually wrong with the car, neither with the HID’s nor with the brake system. Still, it was irritating, so one weekend I set out to fix it.

Being that a few people have had problems with the electrical system (battery, alternator), I figured it was a large instantaneous inrush current causing the car’s voltage to sag and upset the ECU. I had a capacitor left over from the sound system in my last car, so I went ahead and wired it up in the engine compartment. When I turned on the HID’s, the voltage momentarily dropped by about 0.5V. Not enough sag to cause any problem, but the parking brake and ABS lights still came on, so that wasn’t the fix I was looking for.

I checked voltages and ground continuity everywhere; no issues. Okay, so maybe it’s one of the ballasts. I tried each one individually and found that it was the passenger side causing it. That’s when I noticed something that had eluded me so far. The ABS module is located next to the spot where I mounted the relay (on the L-bracket used to secure one of the plastic engine cover pieces). Apparently, when the relay engages, its magnetic coil interferes with the ABS module. Bizarre, really. I can’t imagine the relay producing a very strong stray magnetic field, but the ABS is apparently very sensitive. I relocated the relay to the bolt shown, so that it is basically laying down about 6" away from the ABS module, and the problem is gone....

Installing the HID conversion kit is very easy. Decent kits are plug and play. The Xenon Depot kit I purchased was very straightforward to install. Simply take out the three bolts that hold the headlight assembly and set it aside. I chose to mount the ballasts under the lights (see photo right) to keep them concealed as well as out of the hot engine bay. Judging by its cleanliness, this location does not get wet from rain or water spray. The ballasts and the wiring harnesses are sealed so a little water wouldn’t hurt them anyway.

Then find a location to mount the relay. I mounted them to existing bolts on the engine compartment sidewall, just behind the headlights (see photo). Run the fused 12V leads to the battery, and affix the ground ring terminals to chassis ground.

Use a hole saw or spade bit (in this case, 1.0" dia) to drill a hole in the center of the round bulb cover to accept the rubber wiring grommet. The cover I’m referring to is the sealed cap that keeps dust out of the headlight assembly, and gives access to the bulb to replace it. Fit the grommet in place and install your HID bulbs into the headlight assembly. At this point, it should just be a matter of plugging the wiring harnesses together and re-mounting your headlight assemblies. Fire them up and be sure to adjust the beam alignment to give yourself maximum visibility and prevent blinding other drivers....

Installing HID’s into a vehicle not originally equipped with them from the factory is technically illegal. Practically speaking, you stand little chance of being cited for them provided you educate yourself on the requirements of HID lighting and take the necessary steps to ensure you have the right equipment and adjustments to keep it safe. That is, make sure your vehicle’s headlight assembly uses an appropriately designed projector lense (as opposed to a reflector), and of course that your headlights are properly aligned after installation. Many newer vehicles use projector lenses because stock halogen bulbs also benefit from the "light shaping", but having just any old projector lense does not necessarily ensure that the beam pattern will be correct. It is absolutely essential for HID’s to give the light output a /sharp cutoff line to prevent blinding oncoming traffic. As HID’s become more popular, aftermarket projector housings are being produced for some vehicles.

The Department of Transportation (DOT/) states that improperly-installed HID’s are getting a lot of complaints. Vendors will usually include a disclaimer that they are intended for offroad use only, but it’s no secret that people don’t follow this rule. Now, there are a lot of aftermarket automotive parts that qualify as illegal but aren’t strictly enforced. Logically, the safety implications of blinding oncoming drivers are more serious than, say, an exhaust that exceeds the legal noise level. So the DOT/ has actively gone after vendors of HID conversion kits, threatening monetary fines if they continue selling them, and consequently there are now fewer places to buy them.
 

Most of us spend the majority of the time driving with our low beams on. Compared to the high beams, the lows usually leave the most to be desired.

Let’s look at the diagram from left to right. When you turn on your headlight switch, it puts 12V across the relay coil which in turn closes the contacts. The contacts switch in 12V from the battery to turn on the ballast, which in turn ignites and powers the HID bulb. Pretty simple concept.

A typical HID conversion kit includes:

two bulbs
two ballasts (with built-in igniter)

wiring harnesses
two relays...

The Kelvin (K) is the unit of color temperature. 4100K is the brightest, most natural white light similar to that of daytime sunlight, and therefore the HID color temperature used most in the OEM automotive industry. When you look at the light coming directly out of an HID headlight, it possesses a bit of a blue or purple hue which most people recognize as the expensive, elegant look characteristic of HID’s. For this reason, some HID kit manufacturers produce 5400K, 6500K, 8000K, etc. bulbs that give an even more distinct blue hue but at the expense of overall light output. For comparison, most halogen headlights have a color temperature around 3200K which gives them a "dingy" yellowish appearance compared to HID’s. 

Blue light is more fatiguing to the eyes, both to oncoming traffic and to the driver. Oncoming cars will see your lights for only a brief time, but as the driver, you must deal with it for the duration of your drive. The bluer the tint cast on the road and surrounding area, the more quickly your eyes become tired. It’s a personal choice and I recognize and respect that some install HID’s mostly for the look. However, very blue headlights might get you the wrong kind of attention from law enforcement. Personally, I’d like to benefit from my investment in the way of increased visibility and safety. Be aware that most of the 6500K and higher bulbs are produced by inferior manufacturers to capitalize on the maketability of "the bigger number must be better". Their 8000K bulbs may not measure 8000K. Don’t be fooled.

If chosen properly, the improved light output of HID’s will give you a better field of vision and thus improved safety. Plus, let’s admit it, they look cool.

The best way to describe an HID headlight is to compare it to a more conventional halogen headlight. A halogen bulb consists of a wire filament surrounded by an inert gas. When electrical current is applied to the filament, it glows brightly to produce light. Contrast that with an HID bulb which has no filament, but instead consists of xenon gas, mercury, and metal halide salts. The xenon gas is ignited by an arc of high-voltage current and glows brightly. Also, the high voltage is supplied by a ballast, so in these respects it is like a fluorescent light. HID’s are original equipment generally found on luxury and exotic cars but are progressively finding their way into the mainstream. For example, the 2004 Mazda 3s at ~$17k will include HID’s.