Here is my 2 cents on HID Kits, there has been many rider of many brands and not just Big Dog that has had problems with such. This is not to say that HID are bad of that Jake’s kit is bad, but there has been problems and one can research the many forums from HD to BMW to see some of the problems others have had.
HID do have some advantage that is for sure, however IMHO there is many risk with putting in a kit unless it is a direct retrofit kit from OEM type. HID use a ballast and the bulb is running off A/C verse D/C. The running amperage is much lower the filament bulbs for sure, however the start up is much higher (they work by creating a spark across an electrode –think arc welding-which heats up the xenon gas and as they heat up the amperage drops). The biggest load is at start up.
The ballast is putting out A/C volts and if it is a cheap ballast or has problems, this alone can lead to issues. Proper shielding cannot be over emphasized.
In addition for the most part they are illegal (I know the nature of us is to ignore that) but in this case there is reason. Optics on OEM are well focused to insure that the light is being displayed properly as well as not blinding the other drivers. In a OEM system use low and high beam, there either have two sets of HID or use a shade to cover portions for low beam and remove shade for high beam. Installing a halogen light piggy-back or next to a HID that is not designed for such is one creating extra heat to the Halogen circuit and two make the optics crap.
Many HID kits advertise that they draw 3-4 amps, that is true, however that is after start-up and stabilization, during the start phase and ignition phase a high voltage is used to get the spark to make the Xenon ionized, after that there is the initial phase were the gases are being heated up very quickly by operating at a high voltage. From there the normal operation stabilizes and the stable voltage is obtained and should have a stable arc.
For some of you more tweaker types, that have a HID kit sitting aside, put a good multi-meter on the D/C power feeds (preferable recording type with high-low) and hook up to battery (bench test) and watch the voltage range.
Now since the ballast and the bulb are operating on A/c Voltage at high frequency, any improper shielding can created havoc on the DC side. For some of you electronic type out there, I am sure that you can appreciate this by looking at PLC, alarms and critical Low voltage circuits where shielded wire is very important in many scenarios. Hell for some old time musician that deal with tube amp, think what kind of noise one can get if the D/C side of the transformer is not shielded well.
Now the kits in many cases the ballast is inside an enclosed space with heat being generated by the bulb, ballast, etc. Heat rise create resistance to flow and can deteriorate circuits and components not design for such (remember our cheap plastic headlight connectors). So if the ballast start breaking down, then voltage is not stable and many times one gets the flashing or strobe effect of the light (if the light is not stable due to fluctuation from the voltage via the ballast, what do you think is the effect on the power side which is connected to the rest of the electrical circuit?
Last but not least, assuming a very good kit made with high quality ballast, igniters and bulbs and not some low quality Chinese crap, and then you still have the optics. Great we are running down the road, see a nice bright white light, look cool, etc. Still is the nice white light balance properly with the beam focused to insure that what ahead is seen at best? Or do we get an optical illusion that say hey my light is bright thus it may be better? Let’s not forget the person coming down the road at you, how about if your headlight blinds them and they swerve and run into your ass because they cannot see?
So though I think a properly designed HID would be much better than Halogen lights, until they come up with a proper retro fit, that is DOT approved, I rather lean on the side of safety and possibly sparing the rest of electrical circuit havoc trying to chase down stray joules and PFM (pure f%#king magic) stuff. Combined this with being installed by various level of users, some being much more experience in proper electronics, other just past figuring out how if the light in the refrigerator does indeed go out when the door is closed, well you get the idea.
I will say that if I was going to put a kit on, I would give very high consideration to running wires from the battery directly with a proper fuse to a high quality relay and then let the relay be controlled by the hand control only. That way I am less likely to have the high start up current effect my other circuits as well as the amperage to turn the baby over. The other option, if it was me, would to be to have the lights be switch on after start up either via a timer circuit or dedicated switch, and if not mistaken some of the stuff LowDOwn offer does do this.
Primary choice for me is to get good high quality Halogen bulbs, get the headlight aim right and worry less about something affecting my electronics no matter how good the product is or is not, unless it is a direct retro-fit approved by OEM.