Pinouts of Lionel DCDS.

Look underneath the board  Most are grounds, others are 5V or a specific function like Ditch lights, Firebox etc...  Obviously the serial in and also the Serial out, but I do not think you get a straight answer unless Lionel answers and I think the code may effect outputs.  G

I thought of that George, but none of them are readable, all they are is a smear of white.  They tried to put them there, but were unsuccessful. 

However, I dug through my dead parts pile, and found one that I could read.  Still have to figure out exactly what "Duty" is, and I was surprised to find 3RD there!  3RD is connected to pin 1 of the 6-pin Molex, that's the ground pin.

So, there are ditch lights and their respective grounds, a marker output, presumably and a cab light output.  It's still a mystery if the cab and/or markers are frame ground referenced.  The frame ground suggests that maybe some of those outputs are referenced to frame ground, but that's probably a dangerous assumption.  Serial data is frame ground referenced, but I don't know about the others.  Since there is a ground wire on some DCDS installations to pin 10, I guess the ditch lights have frame ground.

Of course, there is serial data in and whatever Duty is used for. 

I think they are all Frame ground reference.  Which is why those wires need to be cut and moved to a different source when CCM put in.  Markers, Fire Box, Ditch.  Duty out is the serial data (Type) output that goes back to the R2LC or RS input on some applications.  It can be a chuff generator of sorts based on what the DCDS is doing, or trigger a confirmation horn when changing settings as an example.  I know CCM uses it that way and I see it used as an input to Mother board pins typically going to RS Audio Board.   G

I thought the Duty might be a chuff-like output as we had previously discussed.  You are right, pins 4, 6, 8, and 10, all go to frame ground, pin 1 on the 6-pin Molex.  I didn't think to measure the other grounds before.  They didn't have enough room for the GND for the Marker obviously, that one was simply omitted.  

Clearly, this is why the CC-M has a problem with the wiring for the DCDS, none of the stuff on the CC-M is frame ground referenced except the serial data.

John, your grounds are pins 10 8 6 4.    Pin 1 is serial, pin 2 is duty cycle, pin 3 is 5VDC, pin 5 is markers, pin 7 is d/l #1, and pin 9 is d/L # 2.   You know a guy you can email.  

Yep, what exactly does duty cycle do Marty, inquiring minds want to know.  

John, on steam chuff (cherry) switch and (hall) diesel-RPM .  Pin 17 on the R2LC.