Desperately need help.

if I didn’t have table wired, I would of sold out by now.  So I’ve post similar experances but got side tracked. So ok here it goes.  Trains work fine when I turn them on without cars. I run them around track. I then go to power trains down , turn off transformer. Added cars and then put a train on  my inner separate track so I can run 2 trains at same time. I add my mth premier lighted  crescent cars then I put my rail king Berkshire on my outer track with cars.  Both engines are added already in dcs. Power it up, lights come on, go to power up engines says either train not on track when they are well on. Last post I did put I believe  Barry said could be a capiciter or cap thats interfering with signal. Idk what that means or how to fix it. I left train room in Tears from nerves I have watched videos on yutoube excspecially Eric’s trains. I always wanted to live train dream, I’m stuck in a nightmare






Original Post

Let's take a systematic approach to the issue. 

1) Remove the cars and leave the desired engines on the inner track and outer track.  Do they work in DCS?  

2) Tell us how your layout is wired and if there is a separate power supply for each loop, or one power source for both. (Tell us what transformer you have and how it is wired).

3) Check that the engines do not have conflicting (the same) engine ID number.

4) Are both engines in Run mode? (Been a while since I ran MTH engines...)

TCA# 15-70824

Sorry I forgot both tracks are separate ran by z4000 mth. Trains work fine in  dcs without cars. only when I put cars on It messes up. I can start engine and then  train idlyingng and add cars it works. Only when i add cars while train is powered down and then start it doesn’t run saying train isn’t on track. I assume they are in run mode since I ran them for week without cars. Same with road number. They both run with dcs without passenger cars.  The track is wired by mth 4000 going through dcs fixed one to track one and fixed 2 to track 2. Both come out the fixed 2

Totally agree with Volphin’s systematic approach to attempt to identify the problem.

More info would be helpful. What are you using for power?  Are you running conventionally or command (tmcc or dcs)? Are each loco on separate loops or share a common track?

Lastly, please try not to get overly frustrated.

You can have a steam train ...If you'd just lay down your tracks.

Barry said could be a capiciter or cap thats interfering with signal. Idk what that means or how to fix it

You've been advised on other threads that the problem is interference with the DCS signal from one or more of your passenger cars. This is a well-known and fairly common occurrence.

You just need to insert a 22uf (microfarad) RF choke inline with the pickup rollers on the offending passenger car or cars.

This is relatively easy to do by one who is knowledgeable of these things. However, if the task is outside of your comfort zone, any competent MTH-trained tech can can both verify that this is the problem and also perform the task for you.



DCS Ambassador & author of The DCS Companion series of books

Train-Ca-Teers - All For O and O For All!


If some of your cars are passenger cars, turn each one upside down to look at the wires that go from the wheels to the lightbulbs inside. Sometimes, the wires get frayed, or their insulation gets worn away by the curves having been too small a radius, which wears the insulation off by contact with the edge/flange of the wheels. It happened to me. I had no idea what was wrong and was ready to throw a few passenger cars against a wall; instead, I don't know what made me do it, but I looked at the wires coming from the trucks and saw several were worn through, and every time they came in contact with a wheel at a bend, the train short-circuited.


P.S. I fully well realize this phenomenon may have nothing at all to do with what is nettling you, but I just couldn't resist trying to be helpful. If I hadn't tried and later down the long road you had discovered this was your problem, Id have felt badly.

Can I get these  microfarads readily

They're called RF chokes. Microohenries is a statement of the value of the particular component.

They're available from any electronics supply house, such as Digikey. However, you might. be better off getting an MTH-trained tech involved to first verify the diagnosis and then to install the RF chokes.



DCS Ambassador & author of The DCS Companion series of books

Train-Ca-Teers - All For O and O For All!



why don't you come to your senses

you've been jumping over fences

to run a train now...

well, it's a hard one

its a tough one

 but. you're not getting any younger 

you better switch to prewar conventional 

(let your trains love you)

before it's too late...

Barry is the DCS guru, and it sounds like there is a known issue.  I would take it a step further and place a car one by one until I found the offending unit.  Barry, I use Legacy, but am looking at a DCS system as well.  Could you extrapolate why this error occurs with the signal?  Is the signal frequency diverting through the lighting system thus reducing the signal strength? So a resistor is required on each roller circuit?   

TCA# 15-70824

Barry's book will be a great assistant to you, as is Barry here on the forum. Tons of good information in there, a very good reference and worth every penny! 

Hi -

I'm modifying passenger cars by adding two LEDs at each end of the car added as one module at each end of the car (reversed circuit at each end since one truck is base and one is hot)- keeping the legacy center bulb (AF) and soldering one of the LED leads to each rivet of each truck sticking up for a fixture - using the leg for support, I want have found circuits with a capacitor to eliminate flicker. So would this design (using a capacitor) mean these wouldn't work if I took this passenger train to run on a club's DCC S gauge layout?  Typically a choke develops a voltage across it as it instantaneously resists a change in current - do I have that right?  So why does inductance cause his issue?   Should I put a choke in series (I think, parallel too, I could guess, I wonder about an RLC circuit and AF equipment .... anyway, let us know what you find ...                            Tom

It's been know about for some time, it's in Barry's book. As for not adding the fix to the cars, not everyone runs DCS, it would add extra costs, one more thing to have to install during manufacture, one more potential problem, etc. Just guessing here, but I probably hit a couple of things they considered.

Minor technicality, but I believe it's microhenries (uh) for the chokes and microfarads (uf) for capacitors.

Sigh! I fell into the OP's trap and just copied and pasted his misstatement. I've corrected my error.
Thanks for the heads-up!



DCS Ambassador & author of The DCS Companion series of books

Train-Ca-Teers - All For O and O For All!


Could you extrapolate why this error occurs with the signal?

DCS signal degradation is caused by the CV (Constant Voltage) board in some passenger cars and lighted cabooses. The RF choke corrects the problem.



DCS Ambassador & author of The DCS Companion series of books

Train-Ca-Teers - All For O and O For All!


I just wonder why if this a known problem why  doesn’t  makers do this  on passenger cars to begin with 

Some manufacturers now do. For example, GGD (Golden Gate Depot) makes beautiful passenger cars, most of which regarded the DCS signal. Several years ago,  the company changed its design so that the degradation no longer occurs.



DCS Ambassador & author of The DCS Companion series of books

Train-Ca-Teers - All For O and O For All!


This is a suitable choke for passenger cars: 22uh 1.35A Choke at Digikey

This goes in the feed from the center track roller, just put all the power to the lighting through this part.  That should solve the problem of the passenger car killing the DCS signal.

Just an update. Igo out and add crescent Run it, add a car run it, I do it for the cars. Add and run for each car added. Works fine. I then take the crescent engine and cars off. I go to add bershire. No other train stuff on layout. Engine not found. Ok I then add the crescent engine and tender to track. Fire it up. Engine not on track...  jeez so is that even a capacitor thing

 btw before someone ask, yes the engine was on the track 

edit. Berkshire is a railkijg btw if matters  

If you are still having problems with all the lighted cars removed you might have a wiring problem or something elsewhere? I would suggest waiting for Barry's book to arrive and then studying the wiring section of the book. Barry may point you to other parts of the book and I would study those too.

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