How to Make LED Tail Light: The Perfect DIY LED Tail Light Guide


Vehicle tail lamps commonly serve as a safety net for other drivers. However, we may come across a problem: start-up failure. If that ever happens, we face two options to replace them, purchasing new ones or building LED tail lights. While it may seem like a more straightforward solution to buy them, it’s also quite expensive. On the other hand, building one provides many advantages and saves you money in the long run. How to make led tail light, This guide will put you on the right path toward that ultimate experience. So let’s get started!

DIY led tail light: how to make led tail light.

Materials needed:

  • Soldering iron element
  • Wire strippers
  • Side cutters
  • Glue gun
  • Heat gun element
  • Drill
  • Test leads
  • Philips head screwdrivers

Components needed:

  • Red 5mm Superflux LEDs  (strong light output) – 36x
  • 220 Ohm 1/4 watt resistors with 5% tolerance – 9x
  • 75ft Gauge wire rolls – 22x
  • 8ft rolls of 11/64th heat shrink – 2x
  • 5m roll of 10mm heat shrink – 1x
  • 6×8 sheet of Perf board – 2x
  • Glue sticks
  • .022″ Silver bearing rosin core solder – 1x
  • Pull apart OE BMW wires

diy led tail light steps

Step One:

First, gently take out the taillights covering with a Phillips head screwdriver. Turn on the oven to 100°F and place the taillight inside for seven minutes to soften the sealant. Then, pry the lens out gently.  

Create a cardboard template of the tail light. Position it so that it stays far enough from the tail light lens. Mark the top and bottom, so they fit perfectly in the required space. After completing the template, put it on the perf board, which serves as the custom PCB. Next, cut it out with the side cutters.

Step Two:

You can arrange the LEDs in any pattern

(You can arrange the LEDs in any pattern)

Then, place each LED on your perf board in any desired pattern. Because the legs fail to go through thoroughly, you must drill slightly larger holes in the bottom. This ensures they fit nicely.

Step Three:

Use a 3V battery cell to test the LEDs

(Use a 3V battery cell to test the LEDs)

You should test the LEDs to ensure they work appropriately before final installation. To do this, place the + and – sides of the LED on a 3V battery cell. An LED will illuminate if it works as expected. These LEDs contain four legs, whereas you only need two. Use side cutters to remove one positive (anode) and one negative (cathode) end. Now, insert the LEDs in series on the perf board.

This project involves implementing nine rows of four. All the legs need this pattern: + – + – + – + -. The positive end begins inside the board, while the negative ends outside. Then, force the first positive alongside. Next, push both legs downward, allowing the positive to connect along the negative end. Lastly, keep the final negative on one side. Repeat this process for another eight rows. Finally, solder all the positive and negative ends together. You will want to solder the LEDs in under five seconds. Otherwise, it could cause damage.

Step Four:

You will need to connect resistors to the board

(You will need to connect resistors to the board)

The next step involves integrating the 220 Ohm resistors. Connect one resistor end to the LEG’s opposing end outside the board. To perfectly fit the resistor, keep three holes between each resistor end. Shorten the resistor if it’s a bit lengthy. Afterward, solder the resistor end to the LED’s opposing end. Next, bend the other resistor leg, which will fuse to the wire, and shorten it to 1/4 inch.

Cut nine pieces of black wire measuring 2-3 inches long. Strip one end off so that it connects to the resistor. Tin these wires to solder them with the 220 Ohm resistor. Place the tinned wire beside the resistor leg. Solder the wire to the resistor leg. Hot glue the wires on the board, allowing it to move less freely. Cut each to the same extent and expose the wires’ end. Then wrap three together so they will form into a single wire.

Step Five:

Apply the heat shrink on the wires

(Apply the heat shrink on the wires)

Next, cut three pull-apart wires at 8 inches and solder each on the wire bundles. Place heat shrink around the soldered area. You can choose any wire color.

Step Six:

Soldering the wires together

(Soldering the wires together)

Cut short gauge wires. These serve as a custom gauge cluster. Now, wires must connect to the Led’s positive end. You will need to strip and solder the wires to the positive end. Group these in a pair, then solder them with the three long cables to the bundles, similar to the previous step.

Step Seven:

Stripping the wires

(Stripping the wires)

Perform a test to ensure the board works. First, gather the two lengthy wires, remove the three wires’ ends, and wrap them together. Clamp them onto the test leads. Lastly, connecting the opposite test leads to a 12V battery. The LEDs should illuminate. Isolate every wiring connection with an application of hot glue. After cooling down, apply a 10mm heat shrink tube on the long wires’ foundation to prevent damage. Place it inside a light housing.

Why won’t my LED tail lights work?

A bad car battery could cause the LED lights to stop working

(A lousy car battery could cause the LED lights to stop working)

A few factors may contribute to LED tail light bulbs not working as they should. For example, a bad battery may cause it to stop illuminating due to the lack of electricity. You can test the battery’s electrical flow by honking the horn. If it honks, then the battery performs well.

Other times, the LED bulbs may burn out, leading to their power-up failure. To test this theory, remove the light and inspect the filament. A broken filament means that the light will not power. Otherwise, the tail light covers may prove problematic.

Bad filaments could lead to power-up failure

(Bad filaments could lead to power-up failure)

A lousy wiring harness could also cause interference. Inspect the LED tail light bulb wiring on the circuit. Damaged wires or cracked insulation will degrade performance. Additionally, dirty, loose, or broken ground wires prevent the sockets’ current flow. Sometimes a lousy fuse makes the LED lights inoperable. Use a fuse tester on the appropriate tail light fuse to determine if this causes the issue. If the fuse operates as expected, it will illuminate. You will need to replace the fuse with an equivalent size and amperage.

A bad fuse may cause the lights to fail

(A lousy fuse may cause the lights to fail)


  1. Can I put LED bulbs in my tail lights?

Yes. These provide longevity and quicker,more intense brightness than a 2-pin halogen light bulb.

  1. Are smoked LED tail lights legal?

As long as smoked LED tail lights remain visible, they won’t cause problems.

  1. What color LED bulb for tail lights?

Most vehicles include red LEDs for their tail lights. Usually, the color should match the covers.

  1.  Do LED tail lights get hot?

One of the main issues with LED tail lights involves heat dissipation, even though the source doesn’t get hot. That’s because a lot of heat circulates in the emitter.

  1. Do LED tail lights need resistors?

LED tail lights always need resistors connected in series to limit the current. Integrating resistors prevents hyper flash.


Sometimes we face a significant dilemma involving car tail lights simply because they no longer function. This can be problematic, especially when we need to replace them but lack the funds for such an undertaking. If you reach the end of this guide, you understand how to build one yourself, even though it may seem challenging. Plus, this provides you with considerable knowledge of how it operates.

Do you have any questions regarding LED taillights? Feel free to contact us!

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