PIN OUT FOR PS-1 LIGHTING BOARD

Well, most of the leads are labeled.  The brown & black ones say motor, so that appears to be sensing when the engine is moving based on motor voltage being present.  That usually is used to either light something like a MARS light or detect which direction the engine is going.    Since I see a headlight with black wires and the white wires to a bulb on top, I'm guessing it's a MARS light.  The yellow lead most likely brings in track power, I suspect where it connects you'll find a bunch of diodes next to that large cap.

Thanks John. The outputs to the lamps are easy they are already connected and labeled. The yellow wire is center rail and the mounting screws are common outside rail/chassis ground. Just the yellow and common power the mars.cab and the markers with a switch on yellow to manually cut power However the black and brown go to the reverse board not the motor and the only way for me to tell if they receive full power from the motor or are regulated is to re wire the reverse board and power it up and measure what comes off the reverse board. I removed the sound board from the reverse board years ago and paired the sound board with a Digital Dynamics board and I am wondering how or if it's absence affects circuit actions on the reverse board.  I was also wondering if the black wire went to chassis ground but it does not. The only action for the black brown pair seems to be to turn the headlight on or off. If that is the case I can power the headlight with the  R2L CO2 and not worry what is going to the lighting board through the black and brown. Then just use the lighting board for the markers and mars. Guess my title should have been PIN INs for LIGHTING BOARD since the PIN OUTS are obvious. Problem solved, Thanks !           j

That is the function of the brown/black wires, next to them you will see an opto-isolator chip.  That totally isolates the drive from anything on the board.  Without tracing the circuit (only a few components), I can't know how much voltage it can take.  I use a similar scheme with an opto-isolator to sense motion off the motor, my circuit operates from around 1.5V to 18V AC or DC.

I suspect the MARS light is driven from that sense input, because many of the locomotives don't operate the headlight unless the engine is moving. They may also sense the headlight for directional operation, the way to find out is to wire it up and see.  If you wire up the board with nothing on that input, you can see what lights and what doesn't.  The connect a 1.5V battery across it and see if anything changes when you change polarity on those inputs.  The fact that it says MOTOR certainly suggests it was connected across the motor, even if it came from the logic board.

That's a good idea to use the battery. I had considered using one of my $0.40 chinese regulators so I could use it's trim pot to dial it up from O v. The battery will save time. Under rule 17 lighting do they keep the mars light on when the headlight is dimmed? I used your motion detection circuit a number of years till I discovered that a reed relay works. I found some tiny reed relays which are 525 ohms and pick up at 3v. I use a diode if I want them polarity sensitive but it delays pickup a little. Speak of polarity I found by accident that the marker lights/number boards on the Lionel PA-1 reverse polarity when the headlight goes off. I added some LEDs  because the number boards are further forward on the MTH shells and when I reversed the loco the number boards went out. Wondering what happened I took my meter to check and sure enough voltage was there but the polarity had reversed. I never noticed this as long as the incandescent bulb lit the number board.           j

Typically, the MARS light is only on when moving, so when the light dims when you're stopped, the MARS light would be off.

John thank you for the idea of using a battery I did and positive to the brown wire just barely makes the headlight glow. No other changes are apparent.         j

Well, try a 9V battery with a 1K resistor in series and see if that helps get the headlight to full brightness.  I suspect that connection really is the motor voltage, and the greater voltage should help.  However, the 1K resistor is there to protect the circuit in case that's not the case.

Thanks John, I will build something similar to this pix and use small signal relays to control rule 17 lighting.  This is my LESS THAN SUPER CHUFFER and though not very sophisticated works well. Lets me control duration of chuff as well as idle smoke and dims headlight. I use power to motors to switch a reed relay.          j