Where do I start ? Adding ditch lights

[mu26aeh]

I bought a HO Scale Walthers/Proto 1000 GP15 for when I am invited to ops sessions at my friends houses with HO layouts.  I would like to add ditch lights per the proto unit but I haven't delved into the HO world of decoders/wiring before so I don't really know where to start. 

[ednadolski]

To paint in rather broad brush strokes:

 - Decide whether you want LEDs or incandescent bulbs.  Nowadays there really is no reason to go with the incandescents - they are larger, generate more heat, consume more current, and are much more likely to burn out (and need replacement).  The only downside with LEDs is that they are smaller and more delicate to work with.

- Next decide on how you want to connect things to your decoder, ie, what voltage, current, resistors are needed.

- Decide what are the actual parts that you want to use (e.g. Details West?), and how you will install them - where to drill holes and such.

- Decide how you want to route the wiring so that it does not show, and how you want to connect it to the decoder.

Once you have made they key decisions and acquired the parts, it becomes a matter of execution.  Then paint, finish, test and you are done


HTH,
Ed

[mu26aeh]

I've got the LED's, detail parts etc.  I was more concerned with the wiring aspect of the job.  NS had ditch lights on both front and rear, and they flash but I don't think I can get that with the current decoder.  If anything, I'd like to have the front flash, but if both ends need to stay solid that's fine.  I figure if I just want solid lit/always on, I can wire them in with the front and rear headlight.

[ednadolski]

Even if the current decoder doesn't support it, I would still consider wiring each lamp individually.  Then if you ever do upgrade the decoder you could readily implement the flashing that you want.

It may also be worth considering doing the decoder upgrade along with the lighting installation.  More work up front, but then you would save the additional effort that would be needed if you upgrade later.  If you can find a drop-in that would make the job simpler too.

Ed

[jdcolombo]

To add flashing ditch lights, you will need to wire separate LEDs to separate function outputs on the decoder.  It's hard for me to read the decoder number from the photo, but if it is a SDXH166, then it has 4 function outputs.  Two of these will be used for the headlight and rear light, leaving two functions available.  These two functions could be used to wire front flashing ditch lights and NO rear ditch lights, or to wire front and rear  non-flashing ditch lights.  If you want both flashing front and rear ditch lights, you need six function outputs.

Assuming that this decoder has only 4 functions, I agree with @ednadolski that it is better to use separate LEDs for each ditch light.  You can then wire the front ditch lights in parallel to a single function output (function output 3 or F3 as I think Digitrax refers to it), and same for the rear (wired to F4).  You can't do flashing ditch lights this way, but it preserves the option for you to upgrade your decoder in the future to a six-function decoder to permit both front and rear flashing ditch lights. 

John C.

[PaulCoats]

You can wire the front left and rear left in series, and use a 1k resistor, have good brightness.  Do the same on the other side, wired to the other function tab.

Several ways to add ditch lights.  The ones on top of the front and rear walkways will require a suitable casting.  The easiest way is to use the tiny surface mount type LEDs.  They are very difficult to wire, but I have done it.  Better is to buy them with wires already soldered on.  These can be had from a number of sources.  I got mine from ebay seller "Wehonest".

You can mount 1.6mm LEDs just under the walkway on the pilot.  Cut the leads short, solder wires first, and run them back through the pilot.   You'll have to make room on the other side to route the wires up to the decoder, and that is different on each loco.  Here is one I did on some Bachmann GP40's.  Paint the body of the LED with a few coats of flat black, then whatever color is on the pilot of your loco.

And last, you can put the LEDs inside somewhere, and run a "light pipe" made from Plastruct 1/16" clear acrylic rod a la Kato.  Bends can be made by passing the section through a flame and bending.  You'll ruin a few pieces learning how, but you get a lot of these rods per pkg.  I've done this, too.

For NCE decoders, they little instruction manual provided with the decoder tells you exactly how to program CV's for ditch lights.  For Digitraxx, I have never been able to program ditch lights.  I know it's possible, but the 80-something online manual is very confusing. 

[mu26aeh]

Digging this back up from the grave.  Can I cut the green and purple leads coming out of the decoder plug that attach to the DC board and wire them into there, using the blue as the common + ?

[skent]

Yes, you can definitely do that, just make sure that you also attach the proper current limiting resistors for the specific LEDs that you're using. If you are going for flashing ditch lights then be sure to use separate resistors for each LED because if you share a resistor then it will affect the opposite lamp.

I hope that helps!

-S