Originally posted by Eric.S:
Any idea on where to get 5V 3mm 180 degree LED's? I stopped by the local radio shack, but no luck. If i understand correclty, you can get rid of the resistor if you use a 5V led. What if you use a lower voltage led? How do you know what kind of resistor to use? Is there a formula for this? Thanks!!
I haven't found any, don't need 180 degree either like I thought and so I just used the 5mm ones. Nope, have to have the resistor, except for on the master window switch on the drivers side, they are done in series so as long as all 4 led's voltage add up to be more than 13v then you don't need a resistor on that one at least, but if you use 5v led's in there, that's 20V so they might not be that bright as they are having to share only 13 and need 20. As for figuring a resistor, you do it this way, the resistance=(Voltage-forward voltage of led)times 1000, divided by the mA of the led. R=(V-vf)*1000/mA
