This will give you the information needed to make your own LED light bars for lighting your own vehicle. Click any image to view a larger version.

Depending on the specifications for your LEDs, you may choose to have fewer or more LEDs per circuit. The LEDs I got are spec'd for a forward voltage maximum of 4 volts, nominal of 2, so running 4 in series is easily doable in a car's electrical system. The number of LEDs, and the LED's spec also dictates what you use for your current limiting resistor. In my case, I have chosen a resistor that will allow for about 20-40mA depending on variances in my car's voltage output. This is perfectly fine for my LEDs, resulting in them being VERY bright. But you need to follow the spec for your own LEDs to determine such parameters, which is outside of the scope of this HOWTO, and you can find plenty of information on how to determine such things by using Google.

Once you have determined how many LEDs you can optimally use in a circuit, you can then make bars using any multiple of that amount. For instance, I am currently ** a bar that has 12 LEDs in it, and is 3' long...

CAUTION: Hot glue can be very dangerous. IT IS HOT! Although most hot glues will be cool enough to touch just seconds after application, you must be very careful! If you do happen to get some on your fingers, don't panic. Just roll it between your fingers quickly, and it will cool off and peel away. It isn't hot enough to cause major burns unless you manage to drip an entire stick of glue onto your skin, and if you do, you should be institutionalized anyways (or possibly become involved in sexual fetish research?).

First you need your supplies. Some LEDs, drill with a 13/64" bit, resistors for limiting current, PVC pipe, some sort of power connector, hot glue gun and glue. Be sure you have high temp glue, as it will give a more solid result. Not everything is shown in this picture. I suggest LEDs fromBestHongKong.com of at least 6000-8000mcd.

Start by cutting the PVC to whatever length you are going to use, and then slice it lengthwise into two pieces.

Drill the holes out for your LEDs. Try to keep them as equally spaced as possible. I allowed for a larger space in the center to make space for the limiting resistor.

Place an LED into one of the holes.

Glue the LED into place by placing a bead of glue on either side of the LED.

Like so.

Place your 2nd LED, and glue it the same way. Be CERTAIN the LEDs are faced the same direction. With the flat faces all going the same way, or the long leads all on the same side. LEDs will only flow current in one direction, and if reversed, they will not turn on, but simply become burned up little chunks of resin.

Continue in this fashion, gluing in all your LEDs.

Although I did this after gluing my LEDs into place, you may want to test each LED before placing it into the bar and gluing it. This can be done with a 9v battery, by touching the longer of the leads to the positive side of the battery. Do not do anything more than tapping the battery to the leads and seeing if it lights, as prolonged current without a limiting resistor can burn out the LED.

Now we must wire the LEDs in series. Cut off a chunk of stranded wire (I used some spare speaker wire), and strip both ends. Bend the leads of the LEDs in half, and wrap the wire around it. Connect from the long lead on one LED to the short lead on the next. Be very careful not to put too much stress on the leads of your LEDs as they can very easily be pulled from the resin. In this first bar I made, I simply used needle nose pliers to press the lead of the LED hard around the wire to make the connection. This actually works quite well once it is surrounded in glue, however you may wish to, and I do suggest soldering the connections.

Prior to gluing the wire into place, once again use your 9v battery to test to make sure a solid connection has been made.

If both LEDs light, apply glue.

At this point I attached my ground wire. Note the knot I made in the wire. This will come into play later, as a retention point to relieve stress on the connection between the wire and the LED.

Here you can see the resistor I have placed inbetween the two middle LEDs. This basically acts to limit the current in the circuit, so that the LEDs do not burnout. This is a point where I highly suggest using solder to make the connection.

As before, test the circuit before applying glue. If all the LEDs light, glue away.

Continue to wire and glue the rest of your LEDs as I have outlined. In this picture you can see that I looped my power wire back up through the tube, over the top of the solid layer of glue. Again, tie a knot in this wire so that the knot is very close to the other knot once the wires are side by side at the same end of the tube.

Although I don't have a picture of it, I drilled another hole in the other side of the tube near the very end. Push the wires through this hole. The knots then act as a limit so that stress is not put on the leads of the LEDs should the wires get pulled on. This is the last step before gluing the tube back together. Just hold the top and bottom piece together and start by filling one end full of glue and letting it slide down into the tube until you can put more in. Once no more will go in, go along each side of the tube, slowly applying glue into the seam between the top and bottom half. Then just flip it over and do the other end the same way.

You should now have a watertight LED bar, ready to be wired for 12v usage. Just crimp your power connector of choice onto the end. I suggest using molex connectors as used inside a comptuer for an easy to connect and disconnect solution if you're using it in your interior. Or just simple bu