I actually don't see how that can work. The blue wire in all decoders is the +. + goes to the anode of an LED. Bowser locos aren't special, other than they have used LEDs for headlights for a long time, whereas P2K stuck with light bulbs a lot longer (I just replace the bulbs with LEDs when I put a decoder in a P2K loco).
Which side the resistor is on makes no difference, but I pick one side and make all of them the same for consistency. I suspect you had the LEDs backwards to begin with and now have the anode on the blue and the cathode on the function wire as it should be. I have heard of instances where the LED was marked backwards - the flat spot and/or the longer lead for a regular through-hole LED is traditionally the cathode connection. For surface mount LEDs, they sometimes have a little diode image on the underside, or the cathode will have a T shaped pad, or on the top side, there is a dot or notch marking the cathode side.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Hi Missabemodeler:
I'm glad to hear you solved your problem. Personally I don't pay any attention the the anode/cathode stuff. I simply work with positive and negative. If I've got them the right way round the LED lights. Please understand I'm not being critical of your analysis.
If I could make a suggestion, it would be a good idea to post your solution on the original thread as well. That way, people reading the thread will see how things worked out without having to find the second thread.
Dave
I'm just a dude with a bad back having a lot of fun with model trains, and finally building a layout!
Yesterday, I posted a problem with getting the lights to operate when I installed a Soundtraxx Tsunami BW1000 decoder into my Proto 2000 E7A. Thank you to all who offered help. The lights now work. For anyone else with the same problem, it has to do with the anode and cathode of the LEDs. The BW1000 decoder is intended for the Bowser line, not Proto 2000. The way I made it work was to reverse all of the common and function wires. This means that the blue (common) wires with the current limiting resisistors (580 ohm) are connected to the cathode of the LED and the white (function) wires are connected to the anode. The headlight comes on with function 0. I used F5 and F6 for the markers. Hope this helps someones else with the same problem.