Hello,

If you get hold of a normal LED, they'll normaly draw about 15mAmps, and they will normally need around 2Volts.

So you can use the following formula to calculate the size of the resistor needed.

R = U / I

R = Resistanse of your resistor. (What you will calculate)
U = Voltage over the resistor, around 10volts if you have a 12volts supply. (Since the LED will use 2 volts)
I = 15mAmps. (Aproximate value for a LED)


R=10/15ma = 666,67 Ohms

Put a resistor of 670Ohms in serial with the LED and connect it to a 12V supply.

I guess a 1Kohm resistor will be OK for 12-16V supplies, might be easier find around too.

Hope this helps.

TommyE