I am going to install 3V 20 mA LED’s to my locomotives. I will add a ditchlight, cab light,and red tail lights where should I connect the ditch lights, cab light, and red tail lights on a 6 function DCC cecoder board? I have a Digitrax DH165A0
Go to the digitrax website, down load the manual for the decoders and it has a diagram on how to wire it up
For white LEDs rated around 3.5 volts, use a 1K resistor, it will draw about 10ma (the rating for an LED is not how much it draws - it is the maximum it can handle without frying). For red and other color LEDs that are rated around 2.1 volts, use a 680 ohm resistor, that’s about 15ma.
Headlight goes to white, tail lights to yellow, ditch lights to green and violet (F1 and F2) to match the example programming, cab light can go to F3 or F3 which are solder pads for most DH16X decoders.
–Randy