DIY Offroad Lighting




Introduction: DIY Offroad Lighting

Let's make something.

Hello everyone. First of all, thanks for checking out my Instructable! I have been a long time lurker and have never contributed to the community. This is my first submission; that being said, I hope it inspires you to create something of your own.

For this Instructable, my roommate and I were interested in creating LED Light Bars for our Jeeps. During the time that we were working on this project, Light Bars were still running in the $350-$400 dollar range. We frankly did not have the cash to spend on commercial bars. This is where things got interesting.

Neither of us have a background in electronics or anything fancy. We knew the basics and we went with it. Over three years later our design is still fully functioning. Without further ado, the build!

Step 1: Gathering the Materials

So to begin, we really just stepped into the unknown. This was geared with budget in mind, so we bought the cheapest stuff we could find. I apologize for not having specific links to the build list, but this overview should help you get a better idea of the process.

We decided that we would build "pods" that could interconnect, allowing us to make the light bar as big or small as we wanted. With this design we would be able to custom fit our pods to any particular spot on the vehicle.


- eBay star board LEDs (I believe they were 5K, which is a very white light output). We purchased the bulk packs to save on cost and to have extra on hand.

- eBay star board lenses (Throws the LED light output into specific degrees for flood or spot lighting. It all depends on what angle of lens you purchase).

- eBay drivers to provide constant current to the LEDs (Prevents flickering and power spikes from reaching the LED).

- 3M double sided thermal tape to adhere the star board LEDs to the aluminum bar (Also transfers heat from the LED to the aluminum bar acting as a heat sink).

- Aluminum bar stock to mount the LEDs to (Acts as a heatsink and is hollow to allow our wiring harnesses to sit in).

- Foam Spacers go inside of the pod to allow the aluminum bar to sit higher for a snug fit.

- Positive and negative wire (We needed wiring to create our harnesses to essentially daisy chain the LEDs).

- JST Connectors (Allowed us to plug and play each pod to one another).

- Conduit boxes (These were the cheapest and most effective casing we could find for the design. They have a tough body and a removable face with a gasket. The conduit boxes also allowed for us to create our pod system, as they can be attached and removed from one another with small PVC inserts).

- PVC tubing (Allowed us to connect our pods (conduit boxes) to one another).

- Lexan (We used Lexan as our protective lens. It is designed to be vandal proof and can stand up to the elements.)

- Soldering gun and solder (We needed this to create our wiring harnesses for each individual pod).

- Dremel (Used to cut out the lexan lens and the pod lens opening).

- Screwdriver (Used to secure the pod lens to the body).

- Truck bed liner (We wanted to give our bars a rugged look that could take some beating).

Step 2: Cutting the Heat Sinks

Our first real project was cutting the heat sinks. Aluminum is relatively soft and can be cut with a number of hand or power tools. We measured the inside of the pod and transferred that measurement to our aluminum stock so we could create a perfect snug fit. This also ensured that we did not waste any material.

Step 3: Placing the Thermal Tape and LEDs

We created a stencil that allowed for a relatively perfect fit of 12 LEDs per pod. We outlined the stencil with marker and then placed our 3M thermal tape. After the thermal tape was in place, we placed the LEDs onto the tape ensuring that each LED was properly positioned for positive and negative daisy chaining.

Step 4: Soldering and Wiring Harnesses

This is unfortunately the least documented section of our project. We soldered each row of 6 LEDs to each other using small pieces of wire (positive to positive, negative to negative). We then created harnesses using our LED drivers, wire, and JST Connectors (placed at each end of the pods). Each pod was wired identically with a JST connector on each side to allow for easy addition or removal of pods. It's simply plug and play. At the end of the pod that will feed to your vehicle, you simply connect a longer positive and a negative wire.

We ensured each harness was shrink wrapped and very tidy to prevent crossing of wires. The picture above shows the basics of the harness in raw form. You are also able to see the PVC tube spacers and the foam spacers inside the pod.

Step 5: Prepping the Casings

During the process you are constantly ensuring fit, placement and functionality of all components. Once everything is ready, it is time to prepare for assembly. This is also the time to spray paint or bed line for that clean professional look.

Each conduit box comes with a top cover that is screwed in place on each side. The top cover conveniently has a water tight gasket beneath it. The hard part is cutting out the center portion of the top cover to allow placement of the lexan lens. We completed this using a dremel tool and lots of patience. The goal is to leave just enough of a lip so the lexan lens can be siliconed in place.

Cutting the lexan to size is another challenge, but is easily accomplished with proper measurements and the dremel tool again. Once the lexan is cut, you can silicone it to the inside of your top cover.

Step 6: Final Assembly

This is where things get really exciting. It's time to put everything together! It is so simple, it takes just a few minutes. We placed our LED units into the freshly painted pods (ensuring all connections were oriented correctly). We then placed the star board lenses on top of our LED star boards and secured them by screwing on our lexan top cover. Next we placed our PVC tube spacers (which were measured and cut to ensure complete seating of the pods). Finally we plugged all of the JST connectors together and seated the bar fully together by twisting and pushing. It took us some finagling to make sure all of the pods were level and at the same angle.

At this point our light bar was completed and ready to mount. This was easily accomplished by using a $20 commercial light bar harness and simply adapting the bar to fit our specific Jeeps.

Step 7: Operation and Moving Forward

During the course of the last three years the bars have taken a beating and continue to work flawlessly. We have had several comments and interest in our bars, so why not share the knowledge. They are obviously different and provide a unique look compared to the commercial products. We dabbled in selling a few, but the commercial products are too plentiful and cheap for any real market. They do pack nicely to ship though ;)

I hope you have enjoyed this Instructable! I will answer any questions that I can and look forward to posting more projects in the near future!

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    59 Discussions

    Kudos from India. I am interested in this DIY and have already purchased 3w power led chip. Now this is where i need help, I want to make 120w 20"-22" light bar with aluminum heat sink. Can you please help me in selecting the resistors, lens and drivers.
    Thanks in advance.

    Wow, this is outstanding. I have several years of experience installing LED lightbars, lightheads, and similar equipment on emergency vehicles, and these are excellent. While they could stand to have some resistors put inline (one ideally for each LED) to help extend the life of them, the amount of time you've gotten out of them already is probably more than enough for them to pay for themselves already.

    I'm sure there are other viable options out there for housings and such, but what you've got works incredibly well (especially for off-the-shelf materials).

    I may be replicating this idea down the road, and if I do, I'll share any improvements or changes I make with you.

    9 replies

    Hi, I just got all the electronics to make this. What type of resistor would you think is needed?

    Realistically, you don't need anything huge per diode, and everything I've seen on commercial production models is anywhere from 180Ω to 1KΩ apiece. Keep in mind, the higher the resistance, the less intensity you'll get from the diode. If you're wiring all the diodes on each "pod" in parallel instead of in series, you can likely use a 180Ω resistor inline (in series) with each diode, which will help prevent over-drawing your driver while minimizing heat loss and maximizing light-output per diode.

    hey thanks for the information.

    So, just to be sure: I just connect each positive of the diodes together with a 180ohm resistor?
    As with the instructable, I would connect 3 diodes per driver, so that would make 2 180ohm resistors (1 between each diode), or should I use 3 180ohm resistors (also one from the driver to the first diode)?
    And the negatives are connected by normal wire?

    BTW: I got all my stuff from aliexpress, total for (50) diodes, drivers and lenses was about 25euro.

    If anything, use this to help you setup your arrays:


    Source voltage: 12VDC
    Diode forward voltage: 3.5V (this is how much voltage it takes to light up the diode)
    Diode forward current: 700ma (this is how much current each diode uses)
    # of diodes in array: 50 (this is just an example number, it can be whatever).

    The calculator will not only calculate vales of power used/dissipated per diode/resistor, but it'll draw you a schematic and/or wiring diagram. Works very handily.

    Wow, thanks, cool site.

    Just one extra question: the driver states that it outputs 9-11VDC. Should I then use 9 or 11VDC in that wizard?
    I also noticed that there is a difference if I enter 9 or 11VDC (2 in series vs 3 in series).

    PS: sorry for all the noob questions, but I'm more a programmer than an electronics guy :D

    Most of these LEDs should be fine with 10VDC, but make sure to check the data sheet to see what the minimum operating voltage is.

    Realistically, the drivers aren't 100% necessary, since you're already in a DC system that supplies constant voltage between 10 and 14 VDC (average is 12). A direct connection to a distributed power source (e.g. a fuse block) would suffice, but if you're wanting to prevent line noise and voltage spikes from the alternator, a inline simple voltage regulator would work just fine.

    ah ok. Thank you very much for taking the time to help me out :-)
    I hope to get started this weekend with it all :-)

    Just need to check if I got the right resistors in my electronics collection :-)

    Hey I appreciate the kudos! It would be awesome to see what you come up with. If I can help any, let me know!

    Hey I appreciate the kudos! It would be awesome to see what you come up with. If I can help any, let me know!

    In case anyone is interested, I found some similar diodes of varying intensities and color temperatures with or without the PCBs included for a little less:

    Hi this might be a real noob question. But I see that you put the leds in parallel (3 leds/driver).

    The leds take about 3.6-3.8Vdc, but the driver gives 9-11V DC.

    Won't this overload the leds? As we provide too much voltage to them?

    Do you know how much load these light pods put on the electrical system of the Jeep? Is the load equal to the number of LED modules * 3 or do the LED drivers also act as transformers?

    Like any Light Bar there is a main positive and negative wire to power the whole system. Buy yourself a harness (like this one: and follow the schematic that comes with it. There are other options, but for single light bar installs, this is the easiest. If you are going to install mass acessories like in an off road vehicle, baja truck, etc, look at Painless or other companies for their accessory install kits.

    Hey 1775, can you up load some more pics and exact names of the parts you used?

    3 replies

    I can try and find my order history for ya. What type of pictures are you looking for?

    Up close pictures to show your components and assembly shots as you put it together. If you could find in your order history, it would be great to list the specifics if you could. I want to try and reproduce your project. Thanks for the quick reply!