Looking for some guidance/help.

I've decided to deconstruct a "donor" PS3 30-20089-1 GP-20 and put the parts in to a PS1 20-2153-1 F3 A.

The motor in the PS1 is labeled "RS 385 PH" with a brass flywheel.

The motor in the PS3 is labeled "RS 365 SH" with a white flywheel (with tach stripes).  The PS3 has all the parts already mounted to it - tach board, holder, etc.

It feels like the motor mount/gear/etc. from the ps3 slips right into the trucks/gearing from the ps1 F3.  Swapping all the guts one for one seems like it would be the "easiest".  IE. just move the PS3 board and motors from the GP20 frame to the F3 frame without unwiring everything.  Is there any substantial difference between these two motors?

Or should I keep the original F3 motors/flywheel/etc. and re-mount the tach and buy or custom build flywheel tape?

I think I will also keep the F3 CV board/lights.  I assume there is no issue with this.

Thanks in advance.


Original Post

First off, make SURE the gearing of the replacement motor mates with the truck gears properly and runs freely without binding or slop.  If the motor works with the truck, there's no reason not to swap them.  You might slip the other motor into the other truck and see if it had a problem, that might indicate a latent issue with the swap you're considering.

The PS/3 had LED drive for the lighting, so your CV board would have to keep the lights on all the time from track power, you won't be able to control them from the remote.  If that's not an issue, you can keep the CV board.

Thanks - I was going to try the motors mounted in each truck first, just like you said - maybe one is slightly small and the other too large and I got lucky with just checking one....

Below is the CV board from the PS1 F3.

The lights on the right and left are for the number boards.  I'm ok with those being on all the time.

Same with the cab light (the one on the top of the photo), although I'm guessing I could use the PS3 one for that, just to control from DCS.

The white connector is the flashing Mars? light.  I assume I wouldn't get that with the PS3, as the GP20 didn't have that feature.  But if I re-program the PS3 from a GP20 to a F3, do I get an automatic Mars light off a certain connector?

The light below the flashing mars light, I assume is the headlight, and it goes to the blue connector in the photo above.

I had to disconnect the red connector - it goes to main PS1 board (and then I believe it goes into the rear tether, which probably passed through to the dummy A.

I just tested the board.  All lights work fine, except for the main headlight.  But I swapped with an adjacent connector and the headlight bulb works.  So I assume the main headlight is direction controlled, coming off the PS1 board, but I'm not sure how to get it on.  My assumption is that it only comes on when the engine is moving forward and without the PS1 signal, it will never come on, unless I power it off one of the other lights and leave it on all the time, like you indicate.

But I assume I could also use the headlight connector/LED from the PS3 to control the headlight, correct?

If I can get the flashing mars light from the PS3, and a headlight, then I think I would rather just ditch the CV board, as then I'll have lighting control from the remote.

PS - Happy Easter to everyone.


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This is just a guess, however, it might be worth a try.

You could load the PS3 board with the diesel Chain file for a PS32 Upgrade Board and then load the Sound file with an F3 PS2 3 volt Upgrade Sound File. That should give you control of incandescent lighting.

What you'l lose, however, is Rule 17 lighting.



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This is a nightmare.  Buy a kit and do it right.  I would rather have the board in the kit to work with than the nightmare you are talking about.







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The headlight is triggered by the 1.5V outputs of the PS/1 board.  PS/1 supports direction headlights, they're 1.5V incandescent bulbs.  That board takes that input and lights a larger bulb.

Marty's suggestion is certainly valid, one slip with these boards and you're out of luck. 

gunrunnerjohn posted:

First off, make SURE the gearing of the replacement motor mates with the truck gears properly and runs freely without binding or slop. 

I would be inclined to re-use the original motors.  I would be SHOCKED if the worm gear is a perfect mesh, MTH has used so many different ones over the years, with fractions of a millimeter differences among them.  Even if it meshes perfectly, the RS-365SH is a shorter motor making less torque.  I believe the outside diameter of the old and new motors are the same, so the tach sensor should mount the same way.  Making a tach strip with the proper stripe spacing isn't rocket science.

Marty I'm curious about what's different in the official upgrade kit?  I thought all PS3 boards were the same except for software.  Is it  just a question of the correct harnesses, etc.?  Thanks.

Creep, coast, and pull.  We're not talking about cold fusion here.

That's the reason for checking to see if it works properly in both directions.  I agree that it's not that difficult to mount the tach reader, I have tons of the mounts that come in the kits as I frequently don't use them.  You can print the tach strip on shipping label stock, so that's easy as well. 

The pins in the 40-pin connector are tiny, and I suspect he doesn't have either the tool or the pins to modify/add wires.  The wiring harness makes it a whole lot easier to do the install.

For diesel the motor worm is the same thickness.  8mm.  The key is the worm length.  But I would keep the original motors because they are the better motor 385. Mounting tach should not be too hard.

As far as lights a PS-3 diesel board can not drive the bulbs as mentioned even with the correct chain file.  They are not meant for bulbs only LEDs.  Only PS-32 boards can drive bulbs because of the adapter board used.

There is no reason you can't ditch the CV board and go with the LEDs from the GP.  Just match up the connectors.  If you load a PS-3 F-3 engine sound file and chain file for an engine with MARs light you can get that to work too.

As far as bulbs, they are all 6V bulbs, but the HL is controlled by the old PS-1 board via circuitry on the CV board.  That is the extra 2 wires brown and blue normally, that plug into the red connector.   G

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I appreciate the feedback.  Marty - you are right - it is a challenge (and maybe stupid) - but I'm learning a lot and it's keeping me busy.  I am well aware of the sensitivity of these PS3 boards, and the PS3/2 replacements, as I have had issues with two PS3/2 conversion kits already.

I decided to keep the original F3 motors and re-mount the tach board and I had spare 30mm tach tape from a steam conversion.

I'm going with the PS3 LEDs, driven from the PS3 board and ditching the CV board, as I can get all the lights I want from the GP20.  There are extras that I don't need.  However, as GRJ indicates, what I am missing is the MARS light wire from PS3 40 pin connector #35.  I don't have the pins or insertion/extraction tools.

There are a couple items I don't think I need, so I could extract the pins from those locations and move them to the pin I need, if someone has guidance on how to do it without a fancy tool.

Or if there is a part number for a compatible pin (and recommendation on how to crimp without the right tool).  Note I've seen GRJ's recommendation on a different thread for a cheap crimper for the larger pins - I'm probably willing to invest in something like that.

I know this is probably killing some of you - not using the right parts, not using the right tools, etc.

Essentially done.  Adding the smoke unit was a pain, as the PS1 never had one.  Waiting on some LED grommets from MTH, need to dress some wires, and would like to tether the non-powered B and add the rear electro-coupler to the tethered B.

I'm sure it would have been more efficient to use the conversion kit, but for folks that aren't Techs, don't have supplies of spare parts, and/or don't have access to discounted parts, I think I save some $$$ (but spent a lot of labor while learning).


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sf f3 ps1 to ps3

The Mabuchi website gives data on various models and submodels.


You can use a tether to trigger coupler on rear of B unit, but only if it is compatible with your ps2 system.  You can also have a rear headlight.  I used microtronics (?) Tethers.

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