You'll have to be more specific...
Do you mean which pin brings in the illumination signal? -Don't forget that illumination on these is not a constant 12V, but is instead a PWM-modulated pulse waveform.
Or are you actually asking for a constant 12V?
Also, don't forget that there's no such thing as a 12V LED... each colour LED actually has a different forward drop voltage, (red is about 2V, white is often around 4V and so forth) and the CURRENT controls instantaneous brightness, not the voltage per se.
Changing LED colours therefore often significantly alters the brightness, unless there's a CCS in series (Constant Current Source) but usually it's just a resistance to limit the current, and not a CCS, so current flow changes with LED colour.
Originally Posted by VWAddict
The guy i got the LEDs off was having a long chat with me about it all, and he assured me that these LEDs are what most manufacturers use anyway, and there won't be any difficulties.
If there are, i'll fine that out at a later date
I suppose yeah i'm asking for which pin basically illuminates the LEDs, i assumed that it would be a constant 12v supply like you get from a cigarette lighter in the car?