Engines speed slowing down

[SWA737]

 I’ve had something that has recently started happening to several of my Bachman Diesel engines.  7 of them after running for about 10 minutes have started slowing down until they completely stall but the sound continues to operate normally.  After about a 15 minute shut down, they  start running again perfectly for about another 10 minutes then begin shutting down again.  I have 42 converted engines over to railpro decoders. Some are LM-2S’s and some are LM-3S’s.  All are up-to-date with the latest updates.  I have not run any others to see if more of them are doing that. Has anyone had an issue like this? Possibly decoders overheating?  The caution indicator for low-voltage is coming on up to a couple of minutes prior to this occurring. The track is clean and the wheels also. I do have TCS keep a lives in all of my engines.  The engines are about eight years old of which the past four years have been Railpro decoded.

[Alan]

Sounds like the motors are getting hot and the layout wiring is not sufficiently robust enough to cause the LM to over-current shut down.

[nodcc4me]

If seven engines are doing the same thing, they will all most likely do it. In the event that any permanent damage is occurring I would pick one engine and use it for testing purposes until you figure out what the problem is.


You stated this started recently, so something must have changed. Did you make any wiring changes or additions right before this started? If the modules are overheating you should be able to see that by touching the Info button. If the motors are overheating to the point of shut down the locomotive should feel pretty warm to the touch.

[SWA737]

 Nothing at all has changed on the wiring. I have a 12 gauge wire buss going around the layout  with drops every 6 feet and four power units separating the four districts from Railpro.  These engines are the less expensive Bachman sound value engines that are several years old now. Could be overheating motors perhaps.

[nodcc4me]

I don’t think the age of the engines is causing the problem. I am running some very old Athearn, Rivarossi and Bachmann engines, but have not had that problem. Did yours start doing this right after you installed the RP modules or were they running OK? What about your newer engines?

[SWA737]

 I did the railpro conversion about four years ago. This just started recently.  I have a couple of Athearn Genesis engines I will try and see what happens there. Have not run them for a little while. That may tell the story.  I’m assuming if it’s a decoder problem, I would probably get the overload fault or overheat on that perhaps on the HC2?

[Alan]

Pet fur in the mechanism maybe?

[nodcc4me]

That leads me to believe the modules are not the problem, nor the older engines. Check the track voltage with a meter.

[SWA737]

14.2 volts in all 4 power Districts with 2 different meters. No pets in house. Really a mystery. Thanks for all of the thoughts and suggestions.

[William Brillinger]

Is that track voltage test when the issue is happening? If not, check it then also.

[SWA737]

 Well gentlemen, I am embarrassed to say I found the problem. In troubleshooting everything I told you all the track was clean. Apparently it was not. My genesis engines ran very poorly as well. I did a sample area of the track and discovered how dirty it was. I had only cleaned it in the fall but, I had  recently done some electrical work in the drop ceiling installing some additional lighting. I guess it was just enough debris falling to create an issue. I’m sorry I wasted everyone’s time helping me  troubleshoot things.
 Lesson learned.  It does seem like after four years operating the Railpro system, it is much more sensitive to electrical issues whether it’s dirty track, dirty wheels or any kind of low-voltage than the conventional DCC systems I have had in the past. I very much love Railpro but, that is one issue I have found that has been a bit of a challenge over the years even with keep alives installed on all of my engines.  I did purchase two nice atlas engines recently and getting ready to convert them over to Railpro. This time I’m going to try Ring engineering keep alive modules and see if  it helps the situation more than the TCS keep alives I have installed  on all of my other engines.
 Again, thanks for everyone’s help. This is a great forum.
Rob Cooper

[William Brillinger]

Glad you found the problem Rob!

[SWA737]

Thanks Bill

[nodcc4me]

I’m glad you resolved it, but I don’t understand why they took 15 minutes to shut down and then recovered.


Yes, RP is very sensitive to dirty track. My track, running on RP power supply, is spotless, so the engines run well most of the time, but when I run on a DCC layout where the track doesn’t stay as clean, I have had problems.

[SWA737]

 The only thing I could possibly think about the 15 minute cool down and they’re back up and running is, and I am not an electrical engineer, I know just enough about it to get me in trouble but, I believe as voltage goes down amperage would go up causing things to heat up? I’m sure somebody on this forum can correct me if I’m wrong. That’s my only thought process for why the engines start running again after they’ve been power down for a little bit  after attempting to run over the dirty track and pushing through.