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Fixing Shorts When Locos Power Up

Michael S asked:

“I have an DC analog HO scale railroad and following some work on the layout track I am now getting a short which stops me from fully powering. I only get to about 40%. Anything above this and it shorts out. I can wind down the power so the loco starts to slowly run. Is this problem something to do with a turn out?”

14 Responses to Fixing Shorts When Locos Power Up

  • Ken Lambornsays:

    It says locos meaning more than one. Sounds like transformer issue. Have yo tried other transformers?

  • Jim Rosensweetsays:

    Possible bad connection.

  • Lindsay Neilsays:

    Sounds like a ‘slight’ short…If there are power feeds to the ‘new’ trackwork, double check them. If additional points were laid, check their contacts between rails.

  • john Melvinsays:

    You said you did some track work. Did you install a reversing loop? If so it must be completely isolated from the main track and a toggle switch installed to change polarity.

  • Robertsays:

    Does this happen with more than one loco? If not then a loco problem. After track work there may be a nail or metal fragment that has caught up between the wheel and body.
    If this happens with all locos then you definitely have a track wiring problem. Check the polarity of all your connections to make sure one of them hasn’t been reversed.

  • nelson t stahlsays:

    You probably have a short in the track somewhere. Running low power you don’t put enough power in to trip your breaker. If you put an amps meter in series with your track and remove your engine you should see it. It also could be an engine problem you might want to set a small track and try iit.

  • Stephansays:

    Another thing can be checked is the voltage going across the tracks. The reading should be similar throughout. This will also provide the polarities in that the reversed polarity will be opposite of the majority test points. (Using a voltmeter.)

  • Andrew Smithsays:

    Could be damp electrics , use a cotton bud to dry bare electric wires then spray damp start onto electrics carefully . this should do the trick .

  • phil johnsonsays:

    if you are using old Athearn BB powered diesels back to back with KD metal couplers that will cause intermittent shorts. Are these the same engines all of the time? Watch your amp meter. Use a Ohm meter on drivers a d frame

  • Henry van Wyksays:

    One other question, what type of turnout are you using? If it is a peco electrofrog, or any other type that changes the polarity of the frog, that could be wired incorrectly and giving you a short. Also, if it is only one locomotive,check for shorts on the locomotive, like a bit of wire stuck between the left and right side wheels, or a connecting rod touching the body, etc.

  • Wally Gordonsays:

    The answer to your track problem, do you install insulated rail joiners? on both rails though the point.
    I do this on my layout, also return loops must have insulated joiners within the loop. I use a 2 pole center off switches in loop with insulated joiners on both rails on each side of the switch.
    The length of rail between both sets of insulated joiners to be as long as possible.

  • Franksays:

    Sounds like the comments have got it covered

  • Terrysays:

    Unlikely its a short. A short is when you have a direct connection between the positive and negative wires, bypassing the load, in this case, a locomotive, hence the term short. This would trip a breaker or overheat protector.

    Likely you have a loose connection, or you said locos. Perhaps you’re overloading the power pack?

  • Sheldon Clarksays:

    Are you powering more than 1 loco at the same time with the same power supply? If so, is your power supply up to the job of supplying all the amps your locos need? I suspect that when you say, “…it shorts out…” the power supply is being overloaded rather than experiencing a short.

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