LED lighting provides similar illumination abilities to traditional light bulbs, but they do so at a much lower power draw than regular bulbs, and they last much longer. Most LEDs will never need replacement. The device they are attached to will usually fail long before the LEDs themselves do.
You can take advantage of some of the benefits that LED lights offer by building your own motorcycle light. These are usually found for several hundred dollars, but they can be built for pennies on the dollar if you are handy with electrical devices.
Find a lighting fixture that will work for your application. This can be any metal or plastic light that's in its own enclosure. These can be found for a few dollars at auto parts stores or from an online retailer. Make sure the fixture will fit in its intended location, and that it provides a means to easily mount it into place once the light is built. Remove any existing lighting hardware (such as the bulb) to prepare it for conversion.
Pick out your LEDs. The number and type will depend on how much light output you are seeking. Any bank of 12v LEDs will work for this application, though you will probably want to get high-output ones to limit the amount of soldering you have to do. To calculate how bright your finished light will be, multiple each LED's lumen output by the number of total LEDs. For reference, a single car headlight on low is around 700 lumens.
Arrange the layout of your LEDs. It is helpful to lay this out on paper ahead of time to determine what pattern to use. A simple ring around the perimeter of the housing is the easiest to build. If you need room for additional LEDs, a second row inside of the previous one is a good place to start. Mark where each LED will go with a permanent marker. Make sure you leave enough room around each LED to still provide structural stability to the housing.
Find a drill bit that is slightly smaller than the width of the LED (so that it can't slip through the hole), but still large enough for the LED leads to fit through. Using an electric drill, make the holes one at a time. After the first hole, test-fit an LED to see if the size will work. When you are finished drilling the holes, lay all of your LEDs out on your workspace to prepare for the next step.
Insert each LED into the holes one-by-one. After four have been inserted, use a hot glue gun loaded with a clear glue stick to glue the LEDs into place. Simply spread some glue around the base of each LED where it attaches to the housing. The clear glue will still allow light to shine through, but it may dull or distort the lighting, so try not to cover the top of the LED with glue if at all possible. Gluing them in groups of four will help make the job easier since there are fewer loose pieces to keep track of.
Wire the LEDs to the cord that will connect to the 12v power source. Since each LED requires 12v of power, running them in series (where the positive lead of one is connected to the negative lead of the next) is not an option. The power line must be split to each LED.
To make wiring easier, connect a small wire to banks of four individual LEDs, then connect those smaller wires to the large wire running to the power source, that way the power simply branches out to each LED. Use a soldering iron or gun at each connection. To ensure longevity, use heat shrink connectors over each solder joint.
Attach a resistor to the positive power line for each bank of four LEDs. Use Ohm's law of R = V ÷ I (resistance equals voltage divided by current) to determine the needed resistor size.
Wire the power lead to your 12v electrical source (such as the battery or alternator output). Connect a switch somewhere along the circuit that is within easy reach so you will be able to turn the light on and off as needed. Find the desired mounting location for the light, and secure it into place. Screws, radiator clamps and zip ties are all useful when trying to figure out a way to connect the light to your bike.
