P&W B23-7/B30-7 DCC installation

[chsedrumz]

Hello!
I have a P&W P&W B23-7/B30-7 that I want to convert to DCC.  I've got the decoder and I understand how to isolate the motor and connect the correct leads for power to the motor.  What I need help with is correctly wiring the lights.  This engine uses a PCB for the lights.  How can I wire the lights for separate forward and rear lighting.  It appears as if the PCB will only allow both lights to be lit at the same time not separately.  Is there any way to work around this?

Thanks.

[Jim Banner]

One way is to remove the lighting PCB and wire the lights directly to the decoder.  If the lights are LEDs, use a 1000 ohm resistor in series with each one.  If they are not LEDs, consider replacing them with LEDs.  The positive leads of the LEDs go to the blue decoder wire.  The negative lead of the front LED goes to the white decoder wire via a resistor.  The negative lead of the rear LED goes to the yellow decoder wire via a resistor.  Not sure which lead is positive?  Connect the LED to a 9 volt battery, using a resistor in series with one of the leads, and find out which lead goes to the battery positive when the LED lights up.

If your locomotive has incandescent light bulbs, you will have to figure out what voltage they run on and how much current they draw in order to calculate what size resistor to use.  Even if the bulbs are 12 volt types, you may still have to add a small resistor (22 ohms or so) in series with them to keep the initial surge current to a reasonable level.

Jim