Has anyone used the DDM Tuning HID headlight conversion kit, and what did you think of it? I have the HD dual beam headlight and I was wondering what the little square electronic device that comes with the kit does?

 

It is probably the ballast.

 

What does a ballast do?

 

I have the DDM kit in my dual bulb on my 04 FLHT.
This is a simple install. I don't know the mechanics
of it but it has the ballast and the igniter with a
converted H bulb base to a HID bulb. I first put in
the low beam. Liked it enough to install the high
beam. Throws lots of light. Some people say that
you should have a special reflector but this is the
same headlight HD uses to make their HID light.
The one suggestion I would make would be to go
with the Kelvin rating under 5000K to get less blue
and more white light. I also used 35W on both.
They are slow at processing so I would expect at
least 2 weeks.

Jim

 

A true HID bulb is only filled with gas. Unlike a regular bulb halogen with a filament (tungsten wire) that emits light from the resistance of the filament getting almost white hot.

The gas (xenon) between two electrodes which needs to be ionized with a very high voltage (couple thousand) to begin emitting light. Once the ionization starts the voltage is then lowered (around 80 to 100 volts) to what is needed to sustain the ionization with out allowing the light to diminish or go out all together. The ballast is a device that provides this voltage, monitors it and keeps the bulb lit and does various other things, monitors input voltage (12vdc), allows you to cycle on an off a hot (previously on bulb) with out blowing it up, provides itself protection if the bulb does blow up and open the electrical circuit, provide line filtering from the AC they produce to keep the noise out of the audio circuits. The cheaper models don't do all the extra stuff so they don't last as long.

Plenty more info you can search it out.

 

The second question was directed at the wireing that comes with the HD dual bulb headlight, it contains a 2"x2"x1/2" electronic box with 4 wires/ tabs on it.

 

HID means High Intensity Discharge and refers to the fact that the light is not created by a normal bulb, but by the discharge of a high intensity spark. The ballast takes the bike's 14v dc voltage and converts it to 84v ac (alternating current), which is essential for the spark to start up and continue working.

When first turning on a HID headlight it starts humming and the frequency increases for a few seconds until I can't hear it. At the same time the light comes on and gets steadily brighter until it reaches maximum brilliance.

I have a Harley HID headlight in my old Glide. Hope that helps!