Mars light on PK2 E8/9

[Bill O]

I installed a NCE D13SRP decoder in a Proto 2000 E8/9 engine. this one has 8 pin plug and does not require replacing the original lamps. Everything is normal but the mars light. Engine has a regular lower 2 wire bulb for what I assume is the headlight and number board light. Top lamp has 3 wires coming out Red, White & Blue all going to PC board terminals marked R, B, W. I can get the mars to work but it comes on with the headlight also. I can also cut it off and on using F1. Digitrax recommended moving the yellow wire from pin 2 to pin 3 on the 8 pin decoder plug. I did this and the mars started working. I know  I'm using a NCE decoder but this got it to  work. I also have Decoder Pro hooked up and can change the different lighting settings this way also. I'm using a NCE DCC system. Any ideas?  Thanks Bill 

[rrinker]

 What you DON'T want to do is set the function output to be anything but a simple on/off function. Moving the wire allows the decoder to feed power to the Proto Mars light circuit on the factory board (notice there's a lot of 'stuff' on that board, more than is typical for directional headlighs on DC). That circuit handles flipping power between the dual filaments of the special light bulb (that's why there are 3 wires comign from it), so if you want to go that way, you do NOT use any Mars light or other special effects in the decoder.

 A BETTER way to do it is to repalce the special light bulb with either an ordinary one or an LED (NCE decoders work pretty well with LEDs for effects - Digitrax's don't) wired to the green and blue wires. This is F1, or 'output 3' as references in the NCE instructions. In the isntructions under the heading Mars Light it tells you what CVs to then set. The example in the instructions will generate a Mars light effect when F1 is on and the loco is moving forward. The effect provided by the decoder is superior to the dual filament blinker that's part of the loco.

                    --Randy