The headlights of Diablo and earlier cars leave much to be desired in terms of lighting intensity.  Poor lighting often becomes the limiting factor for high speed night driving in these cars.  These days there are a number of aftermarket kits available to allow you to add your own Xenon high intensity lighting display (HID) to your car. What is needed is to replace the  low beam light with HID lights. It is not necessary to replace the high beam lights since the low beam lamps remain on with the high beam. On 1999 and later Diablos the lights are actually Nissan 300ZX units. This makes it easy to find a replacement HID unit.

Figure 1. Diablo Headlights

First a few points about HID:-

What is HID
HID stands for High Intensity Discharge. It refers to lighting technology that relies on an electrical charge to ignite xenon gas contained in a sealed bulb. The technology of HID automotive lamps is similar to that of common vapor-filled street lamps. HID lighting doesn't have a filament but instead creates light by igniting an arc between two electrodes. HID lights get their name from the intense white light produced by the electrical discharge. HID lamps are also called xenon lamps, referring to a gas inside the lamps. HID general lighting has been used for years in sports arenas and stadiums around the country.  Most HID Xenon conversion kits are a simple and affordable way to convert your factory halogen lights to the a HID system. These kits are designed to retrofit head and fog lights of virtually any cars, SUVs and trucks with no modification to the car.

How is HID Different
HID lighting provides about three times the light output of standard halogen headlights while using less energy. HID lights are designed to last up to ten times longer than standard halogen lamps.

Why HID
Some auto experts cite the almost complete darkness on isolated highways as a reason for why HID lighting is becoming popular. HID lights promote safety by providing a better overall view of the roadway and the ability to see upcoming objects quickly and more clearly. For example, road signs and objects on the road are easier to see when illuminated by HID headlights.


What about HID's Color
The color of the light source is expressed as its color temperature. As the color temperature increases, the color of the light moves from yellow to white to blue-white. HID headlights provide light at a higher color temperature than standard halogen headlights, which gives them a crisp white appearance. More K does not mean it is brighter. These 8000K lamps provide a very white/blue color. Kits are usually available in 3 color temperature ranges: 6000K Aqua Blue, 8000K Deep Blue and 10000K Violet Purple. This characterizes the type of light given out. The 8000K lamps are a the most popular.


Are HID Headlights Better, Brighter, Safer
HID lighting provides the brightest illumination available. The more intense, higher color temperature light results in three times the output of standard halogen lighting, which means improved peripheral vision and enhanced down-road visibility. The end result is safer driving for everyone on the road.

Installation

There are a number of suppliers of these kits. I found the group at www.Advantagewholesaler.com to be excellent and provide a good price for their products (see fig 2).  For Nissan 300ZX like headlights you will need their "HID Conversion Kit 8000K HID8000K". The important thing to remember if you are getting a kit from somebody else is that the lights have to be of the "9006" type.

The lights on a 6.0L are exposed behind a panel in the front wheel well. In contrast, in 1999 Diablos, access is through a port at the side of the trunk. I am not sure about other cars. I shall outline my approach for a 6.0L Diablo.  The whole replacement process should not take more than 2 hours.  Jack up the front of the car and remove both wheels. The light access panel is then visible (fig 3). Remove this panel to expose the lights themselves (fig 4). Carefully remove the halogen light bulb taking care not to get fingerprints on the glass (in case you later wish to reuse it).  Insert the Xenon bulb being extra careful not to get finger prints on the glass (fig 5,6) . If this happens clean it with ethanol carefully.  I found the bulbs tight to get into the socket. You really have to push inward as you rotate the bulb. Use a screwdriver to push each of the flanges in as you rotate. It should then snap into place.

Next comes the installation of the power supply.  This is a rather heavy unit. By trial and error I concluded that the best location for it is to attach it to the inside of the wheel well panel we took off. Two bolts hold it in place (fig 7). The only complication is that for one bolt you need to add 3 washer to fill in the curved space of the panel and the flat surface of the power supply (fig 8).  Insert the black input lead of the power supply to the black lead of the cars light socket and the other (red) lead to the cars white (+) lead (fig 9). Cover the wires with plenty of electrical tape (fig 10).  Then attach the output of the power supply to the two leads of the light bulb (fig 11), they go only one way. Check the light works before closing everything up.  Note the position of the power supply on the panel should be such that it does not rub against the light assembly. The position shown in figure 7 gives plenty of room.  Finally put back the wheel well panel.  I have coated the panel with a rubber spray that keeps water out (fig 12 and 13). This way the whole light fixture is kept dry and dirt free.  While this particular cement is brown in color (as shown in figure 12) when fresh, it turns black when dry and does not show up.

Figure 14 to 17 show the before and after pictures. I know there does not seem to be much difference in these photographs. In real life it is much better. Must be something to do with light wavelength sensitivity for my camera.

Fig 2.   HID Kit	Fig 3.   Wheel well light panel location	Fig 4.   Remove light panel
Fig 5.   Xenon light	Fig 6.   Xenon light inserted	Fig 7.  HID power supply attached to panel
Fig 8.   Close up of power supply	Fig 9.  Input for power supply connections	Fig 10.  Cover wires with tape
Fig 11. Output of power supply to light	Fig 12. Seal panel with rubber coating	Fig 13.  One brand of coating