Hi!

You only need a resistor inline with the LED. Here's how to find the value:

Normal Leds drop something like 1.2 V and require 20 mA for full intensity.

You substract 12V-1.2 = 10.8 V that you have to drop at the resistor. R=V/I, so 10.8 V / 20 mA = 540 ohm somthing near that is 510 ohm, or better 560, which will let less current flow through the led, so longer longevity... 10.8V / 560 = 19 mA

As for power of the resistor P = V * I, 10.8 * 19 mA .2 W, a 1/4 W will be fine

So, the result is:

a 560ohm 1/4 W

Included is a picture of such a resistor (for color code: Green Blue Brown and size)

But any value from 500ohm-1kohm would be fine too... same size

And don't forget that leds have polarity, the flat side of the led (viewed from top) goes to the negative:




Hope this helps


Patrick