Hi
I am converting an analog loco (3137) using the 60944 motor upgrade and the 60972 decoder kit. I am still using the original lights, though I plan to change those as well. The locomotive ran OK before the conversion.

When I test out the converted loco, it is not recognised automatically, but is recognised as DCC-3 if I search for it (I am using an MS2).

When I try to run the loco, the wheels turn ca a quarter revolution then wait for a bit, then another quarter revolution. Additionally, if the lights are turned on, they flash once just before the wheels turn.

I have checked the wheels and they seem to be moving freely. I have checked the connections and they seem to be OK.

Can anyone suggest what else I might check?

Thanks for any assistance.

I'll second what bph just posted: check your wiring!!
The behaviour you describe (little jumps, lights "flashing) is usually reflecting a shorted decoder that shuts itself off under overload/shortcircuit

Do not attempt any further "test" before you check this!!

Since you are still using the old lighting set up, you should normally **not ** have connected the orange wire which should be left unconnected if you still have the lights return via the chassis
In doubt, just take a few pics of your wiring and we'll see if anything else may have happened..
Cheers
Jacques

Is the first time that you used this decoder with MS2???

If the decoder is already register on the MS2 then react this way if you use the "FIND" command

Check if the same decoder was registered before.

Or try all the locos that you are not sure what exactly is with the decoder on the loco alone in a programming track

Costas

Your decoder could also have ben “tested” by someone else, and they have disabled mfx. DCC-3 is probably referring to the default address 3 in dcc mode.

Have you tried a decoder reset? I believe you have to do it by enter the cv 8 and value 8, since mfx is not working. How to do it, is described in the MS2 manual).

If the reset is successful, you should the enter the correct motor type, and calibrate it.

Other here might have some other suggestions also. But there is also the possibility that you have a faulty decoder.

You mentioned that you have not yet changed the lighting in your 3137. I could not locate this loco in the Märklin database to see an exploded diagram to determine how the lights are wired however.

Are the lights grounded to the chassis of the loco as they often were in analog locos? If that is still the case the ground for the lights needs to go to the decoder and not to the loco chassis, which can cause issues. I have not seen it cause the problems that you are seeing but I have seen it have other bad effects on digital conversions and that might be worth a check in this case.

Good luck!

On my first decoder install I left the lights grounded to the chassis and you are correct, that did make them flicker but they still worked. But that loco also ran very poorly and a forum member said that could be the result of the incorrect grounding as well.

I actually don't think that would cause it to not register but I have never used an MS2, so I was just guessing. I do know that Märklin says specifically in the installation instructions for gen 3 decoders that everything has to be grounded through the decoder for proper performance.

Hopefully someone else will have better information about this but that is something that I would correct, since it needs to be done anyway. All of my mSD/3 decoders work perfectly and register just as the factory ones do, so perhaps this decoder is defective and needs to be replaced.

I am having the same problem, so I hope a solution is found and posted here.

Steve

Hi in post #4 you say that you swapped the Marklin decoder with an ESU and with this one the loco works.
AFAIK wiring coding for Marklin is different from the wiring coding for rest of world DCC.
How did you manage to get the ESU decoder to work ?
a Marklin loco has Marklin cabling in place and you can't just plug in any decoder

Tom thank you for you input.
I have seen which decoder he's using and indeed it has a 21 pin socket. The wired PCB, the one with the male pins, has two sets of cables coming out of it.
How have this been connected ?
Somebody mentioned to leave only the 4 main cables: motor and track only and see what happens.
Has this been done ?
I have always soldered the decoders directly to motor, track feeds and lights.
I did some conversions using 8 pin sockets but soldered with DCC cabling as I do not like Marklin decoders and I don't care about mfx, but this is my opinion.
I own an ECoS so why bother with mfx.
To be fair even the new generation decoders are a waste of time and 'space' as I will never use more than 10 cv values if I'm lucky and I've always been curious as to who uses all of them :-)

But this is only IMHO and I do not want to start a digita war :-)

Have now installed the new lights (610080/604180) and loco works flawlessly with the LokPilot 4 M decoder.
Marklin mLD3 (21MTC) decoder still not recognised as mfx and same behaviour in DCC mode as before. Firmware checked and up to date (according to LokProgrammer).
Not sure what else to try at the moment.

Can you tell more about the testing of thr 60116?

Regards

Henrik Schütz, Stockholm