Connecting LED, what resistor do I need?

[misbehave]

I want to connect a flashing LED to my P5 near where the door lock is.
The LED I have takes 3.5 volt and the car battery have a 12volt output, so what kind of resistor do I need to drive the current down so that it won't fry the LED, or worse, burn up my car?

 

[Prodigy]

http://metku.net/index.html?sect=view&n=1&path=mods/ledcalc/index_eng

 

[njaremka]

http://autolumination.com/equalizers.htm

just scroll down a little bit, past the flasher modules. none of the flashers will work with the protege, so don't ask. our cars are set-up with a digital flasher module that control a whole bunch of crap.

 

[got wake?]

need to know more about the LED.

 

[njaremka]

forget my previous post, it was still too early in the morning.

you could just get one of these - http://www.cardomain.com/item/VARLL104

 

[misbehave]

forget my previous post, it was still too early in the morning.

you could just get one of these - http://www.cardomain.com/item/VARLL104

LOL! Thanks! man!
Well, I know I could get those.
But I happen to have a whole little bucket of un-used LEDs left over to me by my old roommate who was an engineering students.
So I want to see if I can build my own with those.

 

[BRICE]

Get a LM7805...

Take a look at this

http://www.iguanalabs.com/7805kit.htm

 

[93egt]

something like a 200 ohm resistor should do the trick