Originally Posted by Fred Cooper
I should not have made this post. Had a failure several days after posting. In fairness to DDMTuning, the system has worked great since summer 2010, and I have a warranty ticket started to get a new ballast.
Troubleshooting was not hard, moving the the bulbs proved both bulbs worked, moving the ballasts proved one was defective. On the side with the defective ballast, I removed the HID bulb and reinstalled the old halogen bulb and original wire...so now I have one bright and one not so bright headlight.
Hereís the scoop on HID lighting.
HID lamps are actually a short arc lamp which produces plasma which gives off light in several wavelengths. The light color profile is different than the incandescent lamp. You see HIDs in high end European cars. If the correct light color (Kelvin) is chosen, youíll see further, the target obstacle will be better lit and you suffer less eye fatigue when night driving. Also, HIDs produce about 3300 lumens of light intensity, almost 2X that of the best incandescent.
The HID lamp contains a noble gas to help the lamp cold strike and begin shining. After strike, halide salts are excited into luminescence and you get light of a particular wavelength. The halide cocktail inserted at time of manufacture determines the lamp color spectrum.
Also, in order for the lamp to illuminate, some electronics are necessary, similar to the ballast used in fluorescent lights. At cold strike, the HID lamp needs very high voltage to begin the trip from cold arc to full plasma. The ballast and igniter components provide the required voltage and frequency to control the strike and eventual light output. As with fluorescents, there is a warm up period of several seconds until the HID achieves full lumen output and stabile color.
Inasmuch as HIDs do not use a filament, the light kernel is shaped differently than that of the incandescent bulb. As such, different optics (the headlamp bucket) are required.
Projector optics are used to control and focus the light where it is needed. Also, a mask is located between the HID lamp and the projector lens to control the light pattern and prevent glare for oncoming drivers as well as reducing backscatter for the HID equipped vehicle. Non-projector headlamp optics will produce improved light down road but at the expense of wasted light, light in the eyes of oncoming drivers and excess backscatter.
Typical HID aftermarket systems draw about 10 amps at cold strike. This current draw is reduced to about 3 amps once the lamp is in full plasma (a few seconds). Therefore, headlamp relays are usually recommended to reduce load on the headlamp switch. The ballast will compensate for voltage changes across the vehicle electrical system so you not see headlamp brightness change with engine (alternator) speed.
HID lamps produce little light in the IR spectrum and so, headlamp heat is reduced. However, HIDs do produce some UV. This is undesirable inasmuch as our eyes do not see light in the UV range. Also, UV light produces eyestrain. So choose your HID lamp color with care. The OE HID headlights in automobiles are controlled at 4300 Kelvin. When installing HIDs in any vehicle, select this 4300K color, none other.
Also HIDs reduce electrical system load after cold strike so you reduce electrical system load somewhat. Finally, youíll notice that your HIDs donít burn out. Also they tolerate vibration better than incandescent lamps. After installation, carefully aim you headlights to minimize glare for oncoming drivers.
For those of us who must get our RVs inspected, be aware that an HID installation may not pass the headlamp inspection. And while I have never seen it happen, a non-OE HID headlight installation might draw unwanted attention from law enforcement especially if you choose high Kelvin lamp color (6000K and higher). Stick with the 4300K HIDs.
Regarding quality, most of these aftermarket kits come from China. Quality may be suspect. Deal with a reseller who is in the US and provides a warranty.