i have a athearn c44-9w dcc quickplug engine i am wanting to take the old headlights out and put some bright white led lights into the engine i heard it needs resistors but i have no idea how to wire them i am needing help as to how to wire those and het the lights working in my engine , thanks : )
Many use a 1 k, 1/4 watt resistor in series with one lead.
If you are sure the loco has LED's already, the resistor is probably on the PC board in the loco. I am not familiar with the Athearn DCC setups. Most factory equipped DCC locos have the resistor on the PC board.
Below is a link about using LED's.
http://www.kpsec.freeuk.com/components/led.htm
Rich