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Looking for some help diagnosing an issue.  Recently purchased UP Big Boy LC 2.0 in late December.  Overall the engine is great, but chasing a ghost in the machine that may be related to the engine or tender.  What is happening is that around curves, it seems to cause a quick short in the track, that is immediately reset by the direct lock on and then occurs again, sometimes 3 times or more in a row.  As the breaker resets the legacy signal is still present so the engines moves forward only to trip the breaker again.  Once this series of breaker trips has occurred and it moves past the curve, or I push it past the curve the engine runs flawlessly for minutes/hours with no issues.  All other features are working.  The issue does not re occur until after it is powered off and sits on the track overnight when the issue occurs again.  Below is my set up and what I have currently investigated, hoping someone who owns this engine or has had this problem with another engine can help.

  • engine controlled by cab 2, track powered by 180W bricks through tmcc direct lock on, only run command
  • running on fast track, curves are 048, issue is not common to one curve, occurs at top or bottom of lay out, but only going into or out of a curve and only when in the curve, does not occur on the straight track between each of the curves
  • have cleaned and replaced the curve track and bent pins to make sure I have good contact, and when the short occurs have even wiggled the track to see if that would reproduce or correct the short, but it does not
  • issue only seems to occur once the engine starts up for the first time each day, once it has been running and passes the curve for the first time it does not re occur, even if you shut the engine down and restart, but if it sits overnight it appears to happen the first time it is started
  • Interestingly enough, if start up occurs on a straight section the issue does not occur until it reaches the first curve and again only on the first start after it has sat on the track unpowered overnight
  • I have run other engines at the same time and alone and no others create this type of short
  • I even thought that maybe the smoke unit was drawing to many amps and causing breaker to activate, but the problem exists even with the smoke unit off.  Also of note, after the series of breaker tripping  the smoke unit seems to be super charged for a little while and then resumes normal smoke output, not sure if that is a symptom of the issue or a consequence of the engine powering off 3 or more time in a short timeframe
  • And to clarify when I say short, this is only based on the breaker tripping, I see no sparks as you may see when you have a derailment

I am left not knowing if the engine or tender is creating a short on the track, but not sure why the breaker resets it self without the short being corrected, or is the engine in the curve drawing too many amps and that is activating the breaker?

Appreciate your help in advance.



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I would NOT KEEP POWERING I T UP ! you make damage or blow the circuit boards in the engine either take apart and check continuity from rollers through the engine or look and test for wires pinched in side engine since it's knew why not call Lionel and ask them they make give you a RA authorization number to return it for repair, or they may suggest something to try!

what transformer due you use Lionel or MTH or which one !


Last edited by Alan Mancus

FWIW, I found that sometimes the Lionel TMCC Direct Lockon would trigger on a perfectly good locomotive.  I finally eliminated them from my configuration, and never had another issue.  It would only do so on a handful of locomotives, about 90% or more of my stuff had no issue.  I could never track down any flaw in the failing locomotives, and the were an assortment.  A couple of factory Legacy engines, a couple of factory TMCC engines, and even a couple of ERR Upgrades.  Examination of the engines was fruitless, and they never malfunctioned without the TMCC Direct Lockon or on any other layout.  I had to conclude that something about the lockon was at fault and moved on.

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