Introduction: LED CAR TAIL LAMPS

trying to get better lights for my car i have created an new guide

old car laps used 21W+21W+21W+5W  total 68W used

it is known that bulb lights produce 5% light and 95 % heat so i tried to optimise this by using LEDs

this is how finished product looks like and also bulb/LED light comparison

price for this project is under 50$
i had used zextar leds (12V ones)

Step 1: SIZING

remove tail lights from car and measure the dimessions of original mount and cut an piece of test board (or any isolator) to fit your mount


after you have an basic board you can start to fit as many LEDS as you can for every light bulb replacement

Also you can cut your tail light to an new shape so that more LEDs can enter

test the circuit after every "bulb replacement" assembly to be shure that you did not mount any led wrong

as you can see i have rear light mounter right


mounting all LEDS

to get dimmed light for position lights i have used 12 1N4001 diodes in series with pozition lights

those lights are lit in 2 wais 1 in series with diodes and directly to get full light for brake light



    • Creative Misuse Contest

      Creative Misuse Contest
    • Oil Contest

      Oil Contest
    • Water Contest

      Water Contest

    18 Discussions

    on one  of the other diy post someone said you need a "led compatible" flasher. does anyone know anything about this. as not enough current to start the off /  on cycle in standard flashers. ?thank you pretzel 44

    2 replies

    I replaced my front turn signals on my truck with power LEDs, and you are right they don't flash at the right rate with stock relays. I ended up buying an electronic flasher and disabling the undercurrent sensing circuit inside so that it flashes the signals at the same rate regardless of current draw. Seems that many electronic turn signal relays are based on an Atmel or similar low power microcontroller chips, and cutting a single circuit trace is all it takes to make it LED compatible.

    or may use load resistors in paralell with the diode

    Would be great to have a side by side Incan vs LED pic , Mounted on the car.

    You could also source Clear Lens covers that'll significantly increase final brightness and also look cool!

    looks good. how does the brithness compare with the old ones?

    Is it sad that I saw the bulb holder and instantly knew it was from an Astra GTE (Kadett GSi)?

    I'd not thought to replace the bulb holder entirely, I was planning to make some  bulb based LED's but this has given me food for thought! 

    You may want to visit www.astra-mk2.com it has a great community for the Mk2 Astra/Kadett E.

    You don't mention anywhere using over-current protection resistors or, a voltage regulator, and/or a constant current regulator to drive the leds - without these the leds will die within hundreds of hours instead of hundreds of thousands.

    GREAT instructable with great pictures!  You leave it open to decide how to fit your project to any car.  I like it.

    4 replies

    Do you have the part numbers and where you got them?  I've never heard of that!  That would be awesome!

    this one

    has integrated resistence

    That's really cool; I've never seen those - you should mention that in your 'parts used' step - otherwise someone could do it very wrong!

    Great job again!

    What LED’s are used and where were they purchased?

    1 reply


    i have purchased them from here

    I tried retrofit LED "bulbs" several years ago.  I finally decided that while the LEDs themselves were fairly bright, they only projected a beam straight back.  A real light bulb takes advantage of the reflector inside the lens to project a bright beam visible from a wider angle.  Some autos are designed to have rear projecting LEDs and some have gone back to the incandescent bulbs.  I'm not sure why they have done that, but there must be other issues not apparent to the casual observer. 

    This is a good approach to the task.  I like it if you have bright enough LEDs. 

    1 reply

    I have the led elements out of a cadillac escalade (All led), it has probably 50 leds total, a small brain for pwm intensity control on the lights/signals etc...

    its worth in the plastic housing almost a thousand dollars.

    Thats Cadillac I know, but thats why cars stick with incandescent.  One bulb, apply 12 volts, done.

    There are unidirectional led retrofit bulbs now that take advantage of the reflectors in the housing - they have 120 degree leds aiming in most directions.

    I'd like to see some pics of bulbs vs LEDs and LED brake on vs LED brake off.  This is a great tutorial otherwise!