LED Error Free on the cheap DIY

[sikdogg]

Because you're connecting the resistor in parallel with the bulb, will the OBC know if the bulb fails or burns out?? Has anyone tested this??

[Pdwight]

I can answer that...No

As far as the OBC knows the resister is the bulb, this is the reason for using a "power resistor"

However the LED panel should have a MTBF Life of about 12 to 18 years being run nonstop 24-7 ....so essentially forever . I still have a calculator my dad bought me for Electronics school in 1972 and it is still as good as new.

[sikdogg]

Yea i understand that LED panels have a very long MTBF. I just don't like the idea of disabling the OBC check on a component that's not in plain sight. Otherwise i could just clip a couple of wires to bypass the check and not have to use a resistor at all similar to what people do for the HIDs. It's a no-brainer for HIDs cuz you don't have to rely on the OBC to tell you of a failure. If it goes out... you'll know it instantly.

[wbarfels]

Yeah but on this they last sooo long that it doesnt matter.

What if you wired the resistor between the terminal and one side of the LED? that way when the led blew the circuit would be cut and you would get the warning? might take an extra hour of inventive work, but if your that worried about it........

Actually if you used one of those led panels with the lead coming off it for + and - it would be pretty easy to do......

[baihu]

Like this
http://www.dhgate.com/12v-72cm-72led...b13e76d50.html

[Pdwight]

The circuit is looking for a certain or a given amount of current at a certain voltage to make the circuit (probably a comparitor) appear on to the OBC. If you put the resistor in series with the resistor a part of Ohm's law called current finds the path of least resistance...the led will light but far to little current will be drawn to make the OBC think the bulb is there and working. Until you get the device to draw about .4 amps at 12V it is not going to register as functional to the OBC.

[wbarfels]

Believe me, it works........

And I was using some 12" panels like that just under the lip of the center console in my old car to light the footwells at night, and I have a few leftover that match the red from the electronics that I was thinking of using on the interior of my new car but I cant decide. (hidden behind the center console shining down of course...

[Pdwight]

I meant putting the resistor in series with the led to fool the OBC.....it shouldn't work

[DownUnderBeemer]

Hate to dig up an old thread *ducks for cover*... so no OBC = no "error" per se. Does this mean I can skip the resistors part & there is no damage to my e36? Btw - she's almost legal here... just turned 17, and is an Aussie model [which I believe is imported from Euro, correct?]

[Moron95M3]

Just bought everything I need for this finally...

[jagerking]

Just bought everything I need for this finally...

You know, I'm considering it now. This last weekend, I just installed COMPLETE interior LED's, and they look really nice, especially on my dove interior. The only hiccup I had was the 4 map lights (I have the 97+ with switchable rear map lights). The polarity on those bulbs is reversed, and there is a huge writeup on how to soldier in extra wires, and bypass this and that, and a bunch of other crap. Simpler solution? Reverse the polarity on the map light bulbs. I yanked them apart, resoldiered the 4 bulbs for the maplights (takes about 3 minutes per bulb), and installed. Done and done. Now that I've done those, I'm thinking about making all the bulbs LED. Just need to bite the bullet and get a bunch of resistors, and I should be good. BTW, these days, LED bulbs (either festoons or bayonets) can be had on Amazon for about $2 each. No need to buy on eBay from Taiwan then wait 3 months for shipping anymore! I did the complete interior with several bulbs left over for $22 shipped to my house, including 2 "special" 42mm festoons with 16 LED's each for my dome/trunk lights. The "kits" that are sold cost $100.

[Moron95M3]

UGH! Amazon shipped me the wrong resistors (.68 instead of 68 ohm) so off to radio shack then I'll install tonight I hope


*********************Edit************************* ************ later 'tonight'....



Installed and with great success.


parts:

10W 50ohm resistors from RadioShack ($2.99)


39mm 9LED 5050 dome lights. http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1
$7.99




And install:


remove old:



install new resistor, use some needle noise pliers to curl the ends on, then pop in the LED board.


Test run.





And even more importantly.



Then I soldered it just to be safe (just the resistors).



And then just reinstall...yea the car is rusty




Before:


After:
(mirrored so it's the same angle)



Pretty happy for $11

[Moron95M3]

how they look out at night

[Moron95M3]

btw, looks like you can buy these predone in brackets for $25 shipped. Not a bad option either?

http://www.bmwled.net/xenon-white-18-smd-leds

[jagerking]

Pre-done is nice, but the forum is for people looking to save money. Your resistors + regular LED festoons on Amazon are $5.50. I think I'd just spend the extra 5 minutes soldiering in the resistors like you did and save $20.

[Marv17]

I'm kinda glad I have a 318ti ... Don't have to worry about the resistance for the LED install. No OBC. Just install and drive

[AlpinaM3]

Too much trouble. I just used the German modular ones by Weisslicht (sp) no error at all. They are super bright as a matter of fact almost too much. May tone it down by painting 1/3 of each lens black.