There is no such thing, really, as DCC Ready. There are locos labeled as DCC Ready that have wiring bad enough that the decoder can be eaisly fried if you simply plug it in. Then there are some that it really is that simple, just plug it in and go. And everything in between. You have one of those "in betweens" It mostly works.
If the yellow wire from the decoder is in the hole marked for the yellow wire, there ought to be a path from it to the light bulb. Also, if I recall from wiring one of those, there are more places you are supposed to cut for DCC, not just that one. In my picture of installing it from 13 years ago, I only have one shot that shows the factory board and it's not exactly a closeup so I can't see all the details.
Somethign to keep in mind, most P2K locos use 3V light bulbs, dropped across some diodes for the constant lighting on DC. In the case of the SD, it's those two big resistors that drop the power - and get rather warm. DCC decoders, unless you get ones already set up for LEDs, put out 12-14 volts on the function wires. That will make the headlight a flashbulb. Athearn, until their very recent announcement, has been using 1.5V bulbs in their locos - an even brighter and more brief flash when 12-14V is applied. Plus, those low voltage incandescent bulbs were fine for DC, where you typically run at the lower end of the speed range, with reduced voltage. At least, since you are interested in prototypical light operation, I doubt you run your trains around at full throttle like slot cars. So the bulb is getting less than full power. With DCC, when the headlight is on, it gets full power, all the time (unless dimmed). This can lead to the bulb getting warm enough to soften the plastic - yet another reason I switch all mine to LEDs.
As for Rule 17, I'm pretty sure most of the decoder manufacturers understand what it is. They also undertand that most users don;t wnat to be whacking buttons all day as they run their locos to make the lights do the right thing. Just like automatic directional lighting when that started getting added to DC locos. No, real locos don't automatically change which light is lit when you change the reverser handle. Those that know how it really works are quick to complain how the default Rule 17 action isn't prototypical, but you have to face it, those that know how it really works are a minority. And also, in the early days of DCC, you only had 4 functions in the protocol specifications, and most decoders only had the headlights, no extra wires for beacons or lights (and even then cost $60 or more). This actually is one of the reasons why, back in the early talking days for defining a command control standard, I was is favor of CVP's Railcommand - it had independent buttons on the controller for the front and rear lights! That's because it was developed by and with the support of some serious protypical operators. Not that Bernd Lenz and his crew were unfamiliar with prototypical operation - but what they were familiar with was European operation. The history of the design of DCC does play a part in how things work today, and most do allow you to change from the default automatic stuff to manual control - in this case it is the factory circuit board thwarting you. The fact that the rear light now does not come on at all means it was getting power fromt he headlight, that path is nolonger there witht he trace cut, but the yellow wire has to be in the right palce. I think there is a pad labeled for it, it does not pull from the 8 pin socket one that trace is cut. A limitation that results from them trying to make it fully functional in DC PLUS allow installing a DCC decoder without having to replace the low voltage lamps used.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Randy wrote: "in this case it is the factory circuit board thwarting you. The fact that the rear light now does not come on at all means it was getting power front he headlight, that path is no longer there with he trace cut, but the yellow wire has to be in the right place."
Your points are all well-taken. Thanks for sticking with me so far.
I've come to the conclusion that even though the white wire (F end) works as it should, there's no way I will get the yellow wire to work with the factory circuit board. The version of the Proto 2000 SD9 that I have doesn't have "traces" on the board to slice through with a knife -- instead, it has a black wire with "cut here" printed nearby on the board. No "x's" to be seen.
Before I cut the wire, both lights would illuminate when the R end headlight was activated. After cutting it, nothing. (again F end white wire continues to work correctly)
I tried taking the circuit board off, to look underneath, and consider myself lucky for being able to get it back on. Can't see, and the hands don't work well enough any more for such small components!
I'm wondering if there could be an alternative way to accomplish this -- to do some partial "re-wiring" for the R end light only, without replacing the entire board?
I see the decoder has the green wire "hanging free".
Would it be possible to connect the R end bulb to the green wire, with the other lead (from the bulb) running to a "common" on the board? Perhaps to the common on the F end (white wire)? With a resistor if I need one? Or to another common? (that's the blue wire, correct?)
Then perhaps I could use the green wire function as a simple "on/off" switch to apply power to the R end bulb.
Is this approach possible?
If so, perhaps we can discuss it further.
Regarding "brightness of the bulbs", I'm completely satisfied with the way the incandescent bulbs are working. Bulbs are fine (not overly bright) on full and good on dim. No complaints and I'd prefer to keep both of them as they are...
Can you post a photo of the board? Or several, if needed, so show th ewhole board from front to rear?
Your best bet is to follow the connections from the rear bulb. One should go to the blue wire, this is the common for all functions. The front light should also connect to the blue wire. The other terminal of the rear light should lead up to the point where you cut, since before you made the cut, it got power, and now it does not, and that's the only thing that has changed. There may be other components int he path - in fact there pretty much HAS to be a resistor. For the purposes of following where the power is supposed to go, treat the component as a wire, like the power just goes straight through. It does not matter for this purpose precisely what that component does. The side of the cut that links to the rear bulb is what should get connected to the yellow wire. You can use the green or violet wire, those are just additional function wires, it will just mean a slight change of the CVs to make the proper wire turn on - the way you have it now, the button for the rear light turns on the yellow wire, you will want it to turn on the green wire instead. The dimming may or may not be able to function on functions other than the yellow and white.
OldEnginemanRegarding "brightness of the bulbs", I'm completely satisfied with the way the incandescent bulbs are working.
Many of my early Proto 2000 DCC conversions I left the stock lamps in place or even replaced them with other 14 or 16 volt GOW lamps. I learned the hard way that the built-up heat had distorted, and even destroyed some of my plastic shells.
The designers never figured the heat of those lamps would ever amount to much since, in DC the locomotive didn't operate at full throttle all the time.
In DCC the lamp burns constantly at near full brilliance. The heat builds up quickly. I've ruined two Genesis F units, a couple Proto 1000 RS-2s and the worse was a Life-Like Berkshire that completely melted the headlight off the front of the smokebox.
At the time I did my conversions, white and "yellow-glo" LEDs had not been available. There was a bluish-white 5mm available but not very useful as a headlight.
Loksound decoders, maybe others, have an option to "ramp-up" the LED brightness to simulate an incandescent lamp. It is pretty convincing.
Good Luck, Ed
Here's the circuit board:
(sorry the pic won't post, I'm using microsoft onedrive for storage and even though it provides a link for pasting into message boards, it won't paste into THIS one. You can view the image or download it from the URL below).
https://1drv.ms/u/s!An3uN8X2AHdOgm5EZSGzx9fr0aTr
F headlight is on left (white wire)
Connectors seem to be (on your left)
RR - right side power (f truck)
FL2 - front light
FL1 - front light
LP - left side power (f truck)
Connectors (on your right)
RP - right side power (r truck)
RL2 - rear light
RL1 - rear light (light is removed right now)
LP - left side power (r truck)
There are two additional connectors to the motor obscured by the dcc wires.
The wire that I cut is the black one just above the horizontal resistor.
I noticed that the large grey resistors (is that what they are, or are they something else?) seem to be connected to the "FL2" and "RL2" connectors (I think).
Are these the "common" (i.e. blue) wire?
I'm thinking: green wire --> bulb --> wire to common. But which one?
Could I run it to FL2? I'm assuming the common is "live all the time", so it wouldn't matter if the front light was on or off. Where does the resistor go?
What size/type of resistor? I have next-to-no "pre-knowledge" about working with such components, so you've got to be specific and speak like you're talking to a 10-year-old.
I'm considering just soldering the cut ends of the black wire back together, and running it with both headlights on, and be happy that way...
Do we know the bulb for the rear headlight hasn't burned out?
Henry
COB Potomac & Northern
Shenandoah Valley
I assume you bought this loco used? because that black wire you cut is not stock. The "cut here for DCC" marks a trace on the circuit board that should be cut. It's almost like someone sliced through the trace, then changed their mind, or converted it back to DC, and ran a wire across the cut area. The end that is closest to where the decoder plugs in (I downloaded the picture and flipped it over so the front is to the right - so I could read the markings easier) looks a bit chewed up - you do need to be a little careful soldering to PC boards or you can ruin the traces. That board is similar but not identical to mine. It's hard to follow all of it since there are traces on the bottom side as well.
It appears RL2 comes over to one of those diodes (black things with single band), then goes over to the terminal of a second diode (diagonal trace under the 4 diodes). This then leads to a trace that goes diagonally under the resistor (the greey things are resistors) and over to the decoder plug - presumably to the yellow wire, since it's closest to that. The front light is probbaly reversed, since FL2 got to a diode terminal and ALSO to the horizontal resistor, which then goes over to the vertical resistor and then - who knows, the trace is on the bottom. Guess we need a shot of the other side as well. And if the decoder plugs in - unplug it, as there are traces hidden under the plug.
It's just enough different from my older one that the traces are not all in the same palce. I know witht he one I had, I traced out the circuit diagram and discovered that once you cut the "cut here for DCC" traces, only 1 of the two resistors was still in the circuit. The whole thing made no sense, which was why I ripped it out.
Another approach?
I've just stumbled onto a different solution that might work.
It seems there are several replacement circuit boards available. Instead of plugging in a decoder, these replace the entire analog light/circuit board with a new dcc board.
Here are some examples:
https://tonystrains.com/product/train-control-systems-a4x/
http://www.hiawathahobbies.com/MC2H104AT-DCC-Control-Only-Decoder--Atlas-Others-Board-Replacement_p_31348.html
https://www.traintekllc.com/tcs-train-control-systems-1000-a4x-ho-scale-decoder/
https://www.traintekllc.com/tcs-train-control-systems-1001-a6x-ho-scale-decoder/
(the last one specifically states that it even works with older 1.5v bulbs)
Installation with these looks like it's just a matter of unhooking the wires, removing the old board, putting the new one in place after re-attaching the wires. It may be necessary to put some insulation under the replacement board and tape it down, because there don't seem to be any screw mounting holes that match up.
For me, I'd much rather try this than any "re-wiring".
I'll save the surplus decoders I already have for future installations in "more modern" equipment.
rrinker As for Rule 17, I'm pretty sure most of the decoder manufacturers understand what it is. They also undertand that most users don;t wnat to be whacking buttons all day as they run their locos to make the lights do the right thing.
As for Rule 17, I'm pretty sure most of the decoder manufacturers understand what it is. They also undertand that most users don;t wnat to be whacking buttons all day as they run their locos to make the lights do the right thing.
Over on the Atlas Rescue Forum, there's talk about all the DCC functions you can have in a caboose:
Two kinds of whistles
Handbrake
Coupler clank
Slack running out
Whole lotta "whacking" there. All day.
The only whacking necessary for the locomotive lighting is to dim while stopped for oncoming trains.
Ed
OldEngineman Installation with these looks like it's just a matter of unhooking the wires, removing the old board, putting the new one in place after re-attaching the wires.
Installation with these looks like it's just a matter of unhooking the wires, removing the old board, putting the new one in place after re-attaching the wires.
Some replacement boards just clip on the mounts for the old ones. I've got two Genesis GP9's that I can do that with (TCS A6X). And I did it with an Atlas GP7 (Loksound Direct).
Other boards may not use the same mounting style. I've got some Athearn SD40-2's where I will be using the TCS A6X (1.5V bulbs, etc). I don't think they'll be an easy clip on.
7j43k wrote: "Some replacement boards just clip on the mounts for the old ones. I've got two Genesis GP9's that I can do that with (TCS A6X)."
With the A6x, did you retain the 1.5v incandescent bulbs?
Is anything out-of-the-ordinary required to get 1.5v output on the light tabs instead of "full voltage"?
I tried to find documentation on how to use this feature at the TCS website but couldn't locate any...
Yes, there are resistors built on tot he board to drive the 1.5V bulbs. Other decooders are built to drive LEDs with no extra resistors, those often have a current source that only provides a limited current to the LED - LEDs don;t really care about voltage, just the current.
The problem is, many P2K locos use 3 volt bulbs, not 1.5V like Athearn. You won't blow them up using 1.5V, but they may not be bright enough. You might have to swap them out for 1.5V bulbs to use one of those decoders.
OldEngineman 7j43k wrote: "Some replacement boards just clip on the mounts for the old ones. I've got two Genesis GP9's that I can do that with (TCS A6X)." With the A6x, did you retain the 1.5v incandescent bulbs? Is anything out-of-the-ordinary required to get 1.5v output on the light tabs instead of "full voltage"? I tried to find documentation on how to use this feature at the TCS website but couldn't locate any...
I intend to keep the 1.5V bulbs. I haven't done the installation yet--been busy. I DID see on the documentation that the 1.5V supplies have different tabs than the others. There's 3 ways of connecting things up: 1.5V incandescent, "12V" incandescent, and LED.
I found clear wiring instructions on the Decoder Literature.
And programming in their Programming guide. Including dimming. That's constant dimming, I think, which means you can't change it with a button push. BUT. I noted earlier the idea of have two sources for each location. And, since this decoder is 6 function, that means you can have close to real headlight operation. I think. Now that this subject has come up, I'll likely do this to those two GP9's sitting over on the table.
I do think getting the wires soldered onto the little bitty tabs (some are little, anyway) might be the worst part. I've had years of practice, and I've got a great soldering station. So what's easy for me might not be easy for others.
But when yer playing with little bitty trains, things tend to get little. And bitty.
PS: You MIGHT be able to dim the 12V supply down to 3V, or so. If you start with the lowest dimming CV value, and work up, you likely won't blow a bulb. I hope.
From reading the replies just above, I'm thinking of:
- buying a full replacement circuit board that DOES NOT have a 1.5v output, and then...
- buying new (incandescent) bulbs to replace the 3v bulbs in the loco. They use stranded wire and should be very easy to replace.
I see I can buy a "bundle" of 10 or so replacement bulbs, for about $10 or so, and I'll order them when I order the replacement board.
But... what voltage should I buy?
I see I can get either 12v or 16v bulbs. I'm using a Roco z21 and the track voltage is set at 16v. So... is that the proper voltage to get?
I would instead get a decoder that can handle LEDs with no external components and use LEDs, before I would use 16v incandescent bulbs. Those WILL get rather warm. Plus you'll never have to go inside the loco again, the LEDs will never burn out.
There is no reason to fear LED's. You can buy 3mm warm white leds on ebay from China for 8 cents a piece or a seller in the US for 10 cents. 1K ohm 1/4 watt resistor for 3 or 4 cents each.
Get one of those helping hands,
https://www.ebay.com/itm/Helping-Hand-Magnifier-Glass-and-2-alligator-Clamps-Jewelry-Watch-Repair-Tool/271160862878?epid=710144903&hash=item3f2272689e
and start soldering. After you do 10 you will feel like an expert.
I got some time to try out my solution to the Rule 17 problem mentioned herein. I have posted it as a new topic.
A followup to my earlier posts:
I gave up (at least for now) trying to get the headlights to work on the Proto 2000 SD9 that was the subject of this thread.
Current status -- looks good, runs very well (using Soundtrax Soundtrax MC2H104 OP), considering that this unit had been sitting "new in the box" for many years.
I cut the "cut here for dcc" wire on the board, but after doing so, I could never get the orange wire end to work in any setting that I tried. The only headlight that will illuminate is the F end (which is really the R end on a long-hood-forward engine like the SD9).
But in any case -- I noticed that the factory lighting/circuit board has two large grey resistors that get very hot to the touch when the headlight is used. Since I've read reports of the heat actually melting body shells, I'm not using the headlight at all right now.
I'm still open to getting working headlights "some other way".
First off, a quote from an old Clint Eastwood movie:
"A man's got to know his limitations".
And... I know mine. My vision isn't good, my dexterity isn't so good, either. Nor do I have a broad array of tools, and I don't have a decent workspace in which to use them (if I had them).
So... any fix is going to have to be an easy one.
I'm not interested in LEDs. Any fix will have to be with incandescent bulbs.
I won't be using 3v or 1.5v bulbs. Any fix will have to be with bulbs that run at track voltage (16v). But I don't want bulbs that run too hot.
So I need some knowledge first.
I see the following bulbs available from Circuitron:
800-7440 General Purpose, Long Life Miniature Lamp. 3.0 mm Diameter with Black 12" wire leads. 14 - 16 volts, 30 ma.
This satisfies my criteria for a bulb that runs at track/decoder output voltage. My next question is current consumption insofar as it relates to heat.
A bulb with a lower milliamp rating will run cooler than one with a higher rating, is this correct? I don't mind if they "run warm" (of course) -- just not "too hot".
The 30ma bulbs are about the lowest milliamp rating I can find for 14-16v. My guess is that this will yield a long life, and I DON'T CARE whether they're overly bright or not. All I want is some kind of lighting, even if only "marginally bright".
So... I think these bulbs will do the job.
Comments...?
A 30ma bulb at 16 volts is near a half watt of power. About as hot as those resistors are probably getting. They way to get non-melting bulbs is to use a LOWER voltage bulb, the lowest current 1.5V bulbs you can find, and a bigger (value, not physical size) resistor. But this is not EXACTLY the same as repalcing the bulb with an LED and resistor, except the LED will never even get slightly warm.
As was stated, you can buy decoders that will replace the board in the looco and allow you to connect LEDs or 1.5 volt bulbs directly, the same way you wouuld put incandescent bulbs in a DC loco - no extras, the decoder already has the required current and/or voltage limiting in place, just hook up the red and black track pickups, the orange and grey motor (and if your loco is supposed to run long hjood forward, just reversing the orange and grey wwill make forward be the long hoood end - I do this with all my P2k Geeps for the same reason, they are factory set to run short hood forward but my railroad ran them long hood forward. They even come factory painted with the F on the long hood end like it's supposed to be).
Either type will work. There is no difference to installing LEDs to an LED supporting decoder than connecting incandescent bulbs to one designed for 1.5V bulbs. The wiring is the same.
This version of P2K loco is a real pain to use the factory board - that's why when I did it I just remved the whole mess adn soldered the respective wires in place. If all else fails, there are amny reputable vendors that do the installation for you, but when it comes to hard wiring the decoder in, these are really some of the easiest because they have wires to all the connection points already and it is easy to figure out what is a track pickup vs what is a motor wire. It's the ones where the frame serves as part of the circuit that get more difficult to wire in a decoder.
There are countless videos showing decooder installs - they do not have to be for the exact loco, the concept is exactly the same regardless of who makes the loco. Yoou have 2 wires from each truck for the power input, 2 wires to the motor, 2 wires to the front light, and 2 wires to the rear light. The order of the wires is exactly the same no matter if it's a P2K loco, an Athearn, or an Atlas. It's a fairly large loco so there is plenty of room to work, The same basic supplies will work for every install - some small diameter heat shrink, some Kapton tape, small diameter solder, and a low power soldering iron (25 watts is plenty).