PS3 Diesel Upgrade Kit of P5a 5 volt style

I just started this upgrade and I have a few questions.  

What is the best way to mount the PS3 board?  I have not unwrapped it yet but the new plastic board holder is too long/wide for the engine space.  I believe the board will have to be mounted upside down like the old 5V board was.  It was just mounted using the heat sink.

After stripping everything out and removing the motors to put in fresh grease I noticed that if you turn one motor clockwise the wheels it connects to go forward but the other motor if turned clockwise the idler wheels go backwards!!  So the motors must turn in opposite directions during operation, is this correct?  The motors cannot be reinstalled a different way due to the shaping of the bottom plates.  I also have the motors in the same position as original since I took a picture of the 'old' engine before disassembly.

How do you tell the difference between the POT for the smoke unit and the pot for the volume control.  They are identical with the same color wires but soldered in opposite positions.  Since this engine has no smoke I can just delete the one control but I don't want to cut the wrong one. 

Wires wires everywhere!   Wire management will be most of the time on this one!

So far I have done the speaker and the couplers, relatively easy.  Now the fun starts!

Note how the rear drive wheels protrude up into the chassis plate and the board can't fit between them.  




Photos (1)
Original Post

Don't cut the pot you don't need. Simply wrap it in tape or shrink wrap it. Then tie it up in the harness with the other wires. Most of the boards have a bottom plastic plate with screw holes that hold it down. You also mount the heat sink for the rectifier that also holds the board. This is in the instructions on page 11 and takes up 3 pages! Don't worry about the motors, just make sure the yellow wires go to the harness on page 23. If one ends up running backwards, you just reverse it.

 I think you are not looking at the instructions?

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

I start with the diesel kit by carefully removing all the wires I'm not going to use in the specific upgrade.  You can slide them out of the main connector and just save them for future use.  This greatly simplifies the wiring jungle as the wires are way longer than most installations need, and they also include every possible light and doodad in the harness.


You can also make a new heatsink out of aluminum or copper (whatever is easier to obtain).  Fab it long enough to use as the board mount.  You can eliminate the plastic holder as long as the bottom of the board is clear of metal.

John's tip of removing unwanted wires is also good and will help keep the PS3 rats nest a little more manageable.

Good luck!


If the board is too wide, you can also mount it on a right angle plate on it's side. You can also raise it up if there are obstructions under it. I have to believe that it's not too wide for that engine. How was the original mounted?

 If you wish to remove extra wires as posted above, I use a tiny jewelers screw tip or knife point to pry the harness wire holders so the wire can be removed.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!


This is not in response to your questions, but a comment on the engine.  If your P5a is 20-5510-1 then please continue to read.  If not, you can go back to your PS3 installation.

20-5510-1 was not a great puller because the tach tape was on the wrong motor.  This caused the electronics to wrongly interpret motor input resulting is slippage.  The fix was to install the tach reader on the other motor.  All MTH P5s after this one had the tach reader on the other motor.  I wound up selling the engine instead of fixing it, but since you already have it open I recommend your move the tach reader for improved engine performance.

Now the question would be if you bought this used, was this change already done?  

ADDED: here is the previous topic on this:  20-5510-1 fix





Volunteers don't get paid, not because they are worthless, but because they are priceless!  Author Sherry Anderson

Cappilot:  Thanks, mine is definitely the one with the tach on the motor that drives the single axle!  I will try to change that. 

John/dave:  Thanks, yes removing the unnecessary wires will be a good move, there are a lot of them.  I've spent more time so far trying to untangle the mess!  Making a new heat sink might help too.  Thanks for the ideas. 

Joe, Oh, I read the instructions!  Sometimes it's on the third or fourth reading that I get the idea!   I believe I said the 5V board was mounted upside down using the heat sink bracket.  Simple and nice. 

No info on motor turning direction?  ON page 23 of the manual it  says "ensure both motors turn in the same direction."

The five volt board was narrower than the PS3 diesel board??

I understand it was upside down. Sometimes you have to fabricate something. The kit doesn't know what you are going to install it in. It can't come with everything.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

WOW. I stand corrected. I didn't measure them. So it won't fit in between the shell area or something else like the wheels?

I did just install one into my new scratch build of an ES44 AC. It looked really compact. It is a G scale engine so I have tons of space for an O scale board set. It looked so tiny inside!


" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!


Photos (1)

The 3V board is actually narrower, in it's plastic holder, it's the same width.  However, GGG (George) has mentioned several times there are applications where the 5V board fits, but the 3V board is more problematic.

There's always a way to make them fit, at least most of the time.  However, a few times I've had to extend the wiring harnesses to make a 3V board with 5V connectors fit as the plugs are in a different location on the two packages.

For the P5a, I'd have figured a way to just use one of the replacement boards and not have to redo all the wiring.  I am keeping some 5V boards in my parts box for the day when one of my 5V locomotives eats a board, that will make the fix much easier.

Why won't the metal bracket fit and raise the PS-3 board up above wiring and wheels?  I think I did a PS-32 in a P5 so if that fit the PS-3 alone will fit.  G

MTH Authorized Service Center

Authorized ERR Dealer

Lionel Independent Repair Tech

Virginia Train Collectors Member

Well I used Joe's idea and put 12V to the motors, they definitely do spin in opposite directions but the end result is a forward movement of the chassis!  Good news.  I believe this is because the motors are very close together and the drive axles are on opposite sides of each motor's vertical drive gear. 

I started removing the unused wires from the 40 pin connector.  Still more to go.  

Well will have to do more in a week.  Have commitments for a while.  

OK, I got all the hardware installed on the PS3 upgrade with the diesel kit.  This is not a PS3/2 kit.   Everything was replaced, lights, couplers, board, tach reader, etc.  On initial startup the P5a runs forward and reverse ok.  I am using a Z750 with a controller to do the initial test as in the manual.  

The marker lights go off when the engine is in forward, both the green and red. In reverse all 4 of the marker lights are lit.  The reverse light and headlight work ok as do the interior  lights.  I added the resistor to the red wire of the red marker lights, as stated in the addendum sheet.  

I get no 'test' sound when trying the horn or the bell.  Is this because it is a PS3 upgrade and needs the sound file loaded?

Also there is no PS3 sound file shown on the P5a page.  Can I just use the GG! PS3 sound files?

Also any great ideas on what to do with all the wires?  Wow!  Zip ties to the rescue I hope.  I did not shorten any of the kit wires, I figured it would be easier to wrap them up then cut and resolder.  I also removed all the unnecessary wires from the 40 pin plug.  

thanks for any help.  I think MTH needs to update their instruction manual for the PS3 kits.  



Photos (1)

 Are there pots already soldered on for the smoke and sound? ( with pins 17 and 19?) Mine came with them. Turn them up.

They gave a piece of slit coiled cord organizer with the kit I got to help keep the wires straight.

You could either zip tie or tape the wires to make them neater.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

Joe,  Yes the POTS were there, I removed the smoke one. I will try turning the volume up.   Also got 2 pieces of the slit coil for wire management.  I did not want to neaten everything up until I was sure everything was working ok.  I have the engine up on test rollers so I won't run over any wires!  Thanks

The pot won't have any effect for command operation.  As I mentioned previously, I remove all the wires I'm not going to use from the 40-pin connector to simplify the job.  On the most recent one, I also bit the bullet and dressed the remaining wires and shortened them to what was needed and just eliminated all the excess, it just bugged me to have all that bundled wire!  You can use a PS/2 3V sound file in your upgrade, there are P5a 3V Ps/2 models.  Here are a few PRR P5a locomotives, all have 3V boards.  I see two different sound files, so one may be passenger and the other freight, I'm not sure.

pennsydave posted:

...I am using a Z750 with a controller to do the initial test as in the manual.  


I get no 'test' sound when trying the horn or the bell.  Is this because it is a PS3 upgrade and needs the sound file loaded?


Also any great ideas on what to do with all the wires?  Wow!  Zip ties to the rescue I hope. 

It's for conventional use that I talked about the volume pot John.

He isn't at the command point yet, just testing.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

Well it's done, except for tucking in all the wires.  I loaded the PS3 sound file and chain file for the Premier GG1.  Discovered I was not getting any sound because one of the speaker wires broke loose, I soldered it back on and then lots of sound.  It took me 1.5 hrs to load the software and get the engine responding properly.  30 min to load the sound file, about 15 for the chain file but that all went smoothly. (I am using V5.0 on the TIU) The DCS found the engine instantly but it took me several tries, factory resets, restarts etc before I had it all working together.  I would get Engine not on Track, I would delete the engine and it would stay on the remote.  So I finally deleted all the engines in the remote then shut it all down and left it for 10 min and then restarted the TIU & engine and it was fine.  Even the marker lights are now on, all 4 of them all the time, forward or backward.  Both couplers work, all lights work etc.  

I don't see how anyone does this for a paying customer and manages to do it quick enough to actually make some money!!  I guess after you have done 10-15 you get pretty good at it.  I have only done about 5 so far.  

I loaded the sound files to see how it affected some of the issues I was having.  Did not discover the speaker wire off(covered by a baffle) till after the sound files were loaded.  Fortunately nothing shorted out!  

As I said, I still have to neaten everything up but I want to thank everyone for the help and information.  Also, if anyone else does a Pennsy P5a maybe I can help with some tips.  


If you take out the audio amp on a PS2 board, it's bad. Very bad. Just ask me. I had a screeching sound file that I made the mistake of putting my fat fingers in there while the engine was powered up. It sounded like it was coming from the smoke fan unit. I pushed some wires around and something got grounded and shorted everything. It was a jacked sound file.

I have not done it yet on a PS3. Maybe ask G about that as he fixed my PS2 blunder. I try to be much more careful before powering up anything ever again. If I don't type these replies, I will forget and do it sooner.

So if you got it working, you are doing better than my early tries. Faster? Not me. I take even longer now. No way I could ever charge enough to do it for a living.

" on Sour mash and cheap wine " ??

Why go back to DCC when I have DCS!

pennsydave posted:

I don't see how anyone does this for a paying customer and manages to do it quick enough to actually make some money!!  I guess after you have done 10-15 you get pretty good at it.  I have only done about 5 so far. 

You should put that in large type for the folks that think we charge too much for upgrades.   I can assure you, you won't get rich doing train repairs and upgrades!

gunrunner:  Yes, it's a stressful thing to do, not just in a technical sense either.  When customer are paying someone else for something they expect perfection.  That's why I only do my own.  I can cut a corner or make a compromise on something and it's only me that has to live with it!  I can also take all the time I need.  There are many times I just get so frustrated I have to walk away from it for a day or two to recharge my 'batteries' and think of a solution.  

I was also thinking of how complex our 'toy trains' are these days.  It took over 30 minutes just to load software!!  Hard to believe a pcb that small can hold all those 1's and 0's!!!!  You can almost understand why the Postwar guys don't mess with modern stuff!

Thanks again for all the help and support.   

Still zip tying wires!  

Here is the final product with 7 or 8 zip ties in place.  It might even still run! Note I moved the tach reader to the motor with the traction tired wheels, and could not completely remove the old tach tape on the other motor.  So there are not two tach readers!  It's the front motor or the one closest to the speaker.  The frame is even stamped with the word Front on that end, nice touch.  You have to be careful to leave clearance for the two middle posts for mounting the body, so the wires have to be kept out of there.  



Photos (2)

Add Reply

Likes (1)
Alan Mancus
The DCS Forum is sponsored by

OGR Publishing, Inc. PO Box 218, Hilliard, OH 43026 330-757-3020