SW 8 and DZ 123 decoder

[cudaken]

  "I was this close Chief" as Maxwell Smart would say!

 Hard wire the DZ 123 decoder in to my Proto 2000 SW 8 today. As far as install, it was pretty easy. I used the original PC board as the mounting bracket after I cut off all the didoes and sanded off all the circuits. Was still a tight fit, but got it button up. I used a LED for the headlight using the white wire for the headlight and blue for the common. I have not taken the cab off so I can remove the interior to see if I can get a LED in there with its resistor. I fold up the yellow wire till I get to the back up light. I am very happy with how it runs so far and seems to pull better than I hoped. Pulling 10 coal cars with loads up grade.  

  But Chief, here is the problem. None of the engines wire color codes matched the Digitrax wiring diagram. I had to wing it there. Diagram showed the top of the motor being wired to the gray wire, and bottom being wired to the orange wire.

 Now the engine runs backwards when it should run forward and the headlight only works when it goes backwards? Changed the CV's so forward is backwards. Headlight still only works when the engine is going backwards. I cut the wires pretty short, so I don't know if I can rewire the motor. Few questions.

 1 Is the long hood forward?

 2 What CV do I need to change so the lights are on all the time and to what?

 3 Box says it is a SW8/900/600, is that it's real name? Or could it be a SW 8 or SW 900 or a SW 600. 

 Over all I am very happy with the Switcher. Just like to have the headlamp lit.

 Thanks for the coming answers.

            Cuda Ken

  

[rrinker]

 Just remap the F0F and F0R functions and it will match the changed motor direction. You'll have to remember it's been switched if you later want to change it from soemthign other than basic headlight because forward will be reverse and reverse will be forward. Set CV33 to 2 and CV 34 to 1 (this is the opposite of the default) should do it.

 The way to tell which motor wire is which when they aren't properly color coded (and even when they are - there's not guarantee!) is, assuming it runs the correct direction on DC (NMRA standard says right rail positive, it moves forward - this is obvious for end-cab switchers and cab diesles like F and E units, but hood diesels can get complicated since some railroads ran them short hood forward and some long hood). With it running the direction you want to be forward, whichever motor wire is hooked up to the right rail is the orange one. Right as defined as the right hand side if you were on the loco facing forward - looking ahead of the loco as it mvoes to see what's coming. If the right-hand rail is positive on DC for it to move in this direction, the right rail is conencted to what should eb the orange wire fromt eh decoder. If the right rail is negative in DC to get it to move in this direction, the right rail pickup connects to what will be the grey wire on the decoder.

 Guess the SWs are upside down, the Proto Alco switchers DO have the orange wire as the bottom brush. The NCE decoder I mentioned for the SWs apparantly takes this into account, the wires get connected where they naturally fall and it ran forward properly without changing CV29.

                                           --Randy

 

[fmilhaupt]

1. Long hood is always forward on EMD SW- and NW-series switchers. Pretty much the only hood switchers that were designed with the cab as the front were very early Alco hood switchers and possibly some early Westinghouse switchers.

2. If you want both headlights on all of the time (non-directional headlights), set CV33 to 3 and CV34 to 3, and make sure that CV49 and CV50 are both still 0.

3. SW8, SW900 and SW600 are all different products offered by EMD. They all used the same carbody, though and look identical from the outside.

[cudaken]

 Fritz, that took care of the lights, Thank You.

 Randy, the colors of the wires only threw me when I was grabbing them to solder. Engineer side truck wires where blue, like the common for the lights.

                        Ken