LED number plate bulbs

[alex020869]

Does anyone know what size of resistors these bulbs would need. Thinking i may just get the no-resistor LED's and fit resistors myself to save any hassle.

Alex

[PetrolDave]

Does anyone know what size of resistors these bulbs would need.

It's a simple Ohms Law calculation.

The LEDs take so little current you might as well assume they consume 1W.

So for a 21W bulb you need a resistor that will dissipate 20W, since R = V * V /P and V = 12V that means you need a resistor of about 144/20 Ohms i.e. 7 Ohms. The nearest standard value to that is 6.8 Ohms - so you want a 6.8 Ohm, 20W (or greater) resistor.

[alex020869]

Thanks mate. Good thing to remember.

Alex

[stuartbarriskell]

LOL, not been on for a few days, never realised this number plate thing was such a contentious issue... anyway, looks like we don,t have an easy solution, don't fancy this reisitor fitting scenario, think I will just live with the "yellowish" OE stuff....after all I rarely if ever see them..


Was a good chat for all anyway :=)

[scaghead]

LOL, not been on for a few days, never realised this number plate thing was such a contentious issue... anyway, looks like we don,t have an easy solution, don't fancy this reisitor fitting scenario, think I will just live with the "yellowish" OE stuff....after all I rarely if ever see them..


Was a good chat for all anyway :=)

you get back on the whisky fella...

[ArthurPE]

a couple of questions:
wattage of oem bulbs
are they in series? unlikely, if one bulb is pulled do both go out?
parallel?
or seperate circuits for each (supply/sensing per bulb from the controller)?
anyone have a wiring schematic for reference?

if in parallel one resistor would do it...

some good info http://nickscarblog.com/diy/led-license ... 005-5-2008

this link would indicate in parallel, ie, one balancing resistor http://www.audizine.com/forum/showthrea ... late-light!!

[PetrolDave]

a couple of questions:
wattage of oem bulbs
are they in series? unlikely, if one bulb is pulled do both go out?
parallel?
or seperate circuits for each (supply/sensing per bulb from the controller)?
anyone have a wiring schematic for reference?

According to the wiring diagrams I've seen they are separate circuits.

[Stoffle32]

hey all

Sorry for the late reply, seems these Rs4's are very temperamental...
So on the weekend took the Rs4 out, and I got a warning when started the car said the number plate light was out, got out the car to check was all working fine...
The warning however did not stay like it usually does it just flashed once then went away, and if you push the check button it does not come back...
What is strange though is, I dont leave my car parked in Auto for the lights, unless im going out that night etc... If you leave it on auto the error does not come up at all
So this is confusing me a lot, however reason why I have not posted the link is because i want to speak to were it comes from to find out exactly what is happening before a bunch of you go out and purchase them and they give you an error...

[scaghead]

stoffle i know what you mean fella, one of the sets i brought worked fine for a day or so then chucked up a fault code intermitently... good luck fella hope you get it sorted

[lma07]

I get the same error periodically on my led rear lights. Right fog light. It is working but sometimes get the dash warning light appear

If I switch off auto lights it's happy but I prefer to keep auto lights on (it's too much effort to switch on my lights manually)

I spoke to Danny at the national gathering and he said there is a code on Vagcom that you can use to correct it.

[Vlan_One]

hey all

Sorry for the late reply, seems these Rs4's are very temperamental...
So on the weekend took the Rs4 out, and I got a warning when started the car said the number plate light was out, got out the car to check was all working fine...
The warning however did not stay like it usually does it just flashed once then went away, and if you push the check button it does not come back...
What is strange though is, I dont leave my car parked in Auto for the lights, unless im going out that night etc... If you leave it on auto the error does not come up at all
So this is confusing me a lot, however reason why I have not posted the link is because i want to speak to were it comes from to find out exactly what is happening before a bunch of you go out and purchase them and they give you an error...

I picked up the same set as yours from the same supplier yesterday, put them in this morning and worked without any error. During the day I got in the car pressed the start button and found the same problem. I got the quick message about the number plate lights and it also went away immediately and pressing the check light revealed nothing. I then tried switching off the car even took out the key and on every start after that, no error. I always leave the lights in auto and have coming home enabled. Seems to be only on the first start after thew car stood for a while.... hope it helps to establish a pattern.

Have you spoken to the supplier yet?

[DazN]

Does anybody know if I went down the route of LED lights without built in resistors do I then have to add 1 resistor per light or just 1 resistor on the 'loom'?

Reason for asking is I have just fitted a rear view camera and that has an LED bulb in, which is now giving me this error, so I want to change the opposite light and then add resistor(s).

I have noticed a few places on eBay that sell a pair with built in resistors for <£30, I could buy a pair and just fit 1?

Thanks

[DazN]

And are these suitable resistors?

http://www.ebay.co.uk/itm/Load-Resistor ... 654wt_1139

[mikeypur]

would these do the trick?

http://www.ecstuning.com/Audi-B7_RS4--V ... ES1899488/

or would you need a resitor fitted along with these?

[MB2]

Those are the "racing dash" ones, & didn't work with my car (triggered errors & flickered) although work or not seems a bit variable car by car.