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D3 - Lights Headlights, xenons, foglights. Everything outside the car that glows

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  #31  
Old 12th January 2020, 11:22 AM
ainarssems ainarssems is offline
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One of the boot lights was filled with water so took it off to drain and to try and reseal it. Measured voltage on LEDs while I was in there and they run at 1V when tail lights are on and 1.7V for brake light so need 1.8-2V LEDs. I did not have time to unsolder one and test the current. I see there was 5V mentioned before but using 5V LEDs they would be very dim.
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  #32  
Old 12th January 2020, 11:23 PM
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ivanhoe ivanhoe is offline
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The link I posted has the specs.
Those leds have been tested in the a8 lights and confirmed ok.
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  #33  
Old 10th October 2020, 09:38 PM
ainarssems ainarssems is offline
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I bough 500 LED pack from Amazon back in January https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1 , got the 500 pack as that was in UK available for next day delivery but did not get to change them until end of July. At this time more than half of LEDs were not working on the drivers side wing light so I changed all of the LEDs in that light. At the time noticed that couple of yellow indicator LEDs were not working as well so ordered 50 pack from the same seller on Amazon as the 50 pack was on UK stock for yellow. Unfortunately they sent me red ones not yellow. Got a refund from Amazon and they told me to keep red ones. I then bought yellow on ebay. https://www.ebay.co.uk/itm/5mm-Water...53.m2749.l2649

The red ones are indistinguishable from original on car when lit but they do not last. After about 3 weeks all on one PCB failed, I replaced again, after another 3 weeks another PCB failed, replaced again. 3 weeks later one PCB failed again. I have not measured the current, maybe they are driven a bit hard. I will test adding some 5W resistors to see how much resistance I can add without loosing brightness and see if it can help them last longer.

No problems with yellow ones yet but they are only on for short periods of time.
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  #34  
Old 7th November 2020, 03:21 PM
ainarssems ainarssems is offline
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Finally did some measurements.

It was 1.3mA going through each LED with tail lights on and 23mA with brake lights on so no wonder replacement LEDs kept blowing after 3-4 weeks of use as they are rated 20mA. There are 3x 4.7ohm resistors in parallel on one of PCBs which should be 1.6 ohm total, multimeter reads 2ohm. I added 2 and then 2+2 ohm in series in one of the wires and with extra 4ohm current went down to 20mA, I cannot notice any drop in brightness at least not in daylight, will check again when it gets dark.

I will leave it like this for now with a total of 5.6-6 ohm. But will get 3x22 ohm SMD resistors to go in place of original on PCB and replace if LEDs fail again and I need to go in there again. This would give about 7ohm total and bring the current a bit more down to give a bit of margin.
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  #35  
Old 8th November 2020, 05:09 PM
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Thanks for updating. Interesting. 😎
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