Now I am trying to install a decoder in a P2K FA1. I tried a DH123 plugged into the board and the engine runs but no lights. I want to replace the headlight and mars light with LEDs. The mars light has three wires from three pins on the board and the headlight has two wires from two pins on the board.
How do I wire the two leads from the mars LED to the three pins on the board?
The answer is to unplug the decoder and rip out the light board that comes with the engine. That way, you are not guessing on what is actually on the board.
This is a very simple hardwire and a great way to get your feet wet beyond the plug and play stage. I would suggest getting a Golden White led and a red one and then put them where you want them. Then use 600-1000 ohm resistors inline with the white and yellow leads from the decoder (which go to the short legs of the LEDs.
David B