resistor question

[DavidEnghauser]

Can I wire two LED lights together and use one R2.1k resistor to take the 3 volt lights to 12 volts?

Thank you,

David

[Rog (RJ)]

Two LEDs can be wired in series with one resistor but wired in parallel it is far, far better to have one resistor per LED. If wired in series, you may want to use a lower value resistor to get maximum brightness but usually LEDs are too bright for model railways when they are at full power.