I'm in the process of changing the color of my defroster button. So far is have changed the HVAC and A/C button to blue using the 2700mcd Blue led. Now I want to change the defroster button to red, the brighest LED they sell at Radio Shack is a 10mcd LED. My question is what resistor do i use? I've already installed it using the same resistor as i used in the A/C and HVAC controls, but the red it too faint and only shows up at night. Is the resistor too strong?


Thanx~:thumbsup

I'm not sure about resistor, but a 10mcd LED isn't that bright at all.. mcd is the brightness and if it's only 10mcd it's probably not that bright.

That was the brightest they had. Do you know of any other place that would have brighter LED's?

(Vcar-Vled)/Aled = R

Vcar is the Voltage of the car, assume 14V to be on the safe side.

Vled is the Voltage the led is rated to (you'll find it on the package)

Aled is the current rating in Amps of the LED (also on the package and remmember 1mA =.001A)

R is the resistor you'll need in Ohms. You won't find a perfect match so use the resistor that's closest.

Keep in mind that the bigger the resistor the dimmer the LED will be, but you use to small of a resistor you could burn it out.

10mcd won't light up anything.