Help with MTH ScaleTrax No. 4 Switch

Turn the lights off, make the room dark and slowly run your big stuff into the switch. A fat spark should indicate a short.

CUT power as fast you can and turn the lights back on. Somewhere there should be a metal contact where it should not happen.

You say you are running a number 4 switch. I will GUESS that your bigger engines need a bigger number 6 switch MAYBE.

That is all the thoughts I have going on what little you provided.

Thanks I will try it out and provide more information

Thanks I will try it out and provide more information

Matt,

   Glad the videos helped.  Hope I can help with this.  Finding the short is good advice.  I find it by running the engine through the switch at the slowest speed possible.  When it hits the short it will stop.  I turn the power off then tilt the engine a little to see where the rollers are and short is.   Its not so much the size of the engine as it is the roller spacing.  Larger engines have more or just a different spacing which exposes a different problem.  When the engine stops check to see if the roller is on top an touching both a power rail ground rail.  The only ground rail it should touch is the one crosses through the middle of the other side of the switch.  That one should be isolated.  There are two of these on each switch, one for each direction of the switch.  You may have fixed one of them, but when you throw the switch the other way, the other rail comes into play.  I'm betting that your RailKing engine shorted in one direction, and your bigger engine shorted in the opposite direction.  So just make sure both of these ground rails in the middle of switch are isolated using the method Dave suggested.  Let us know how it works out.

Rich

Rich

Thank You - that fixed the problems and the trains are running with no issues and no shorts. Appreciate the help and the videos and if you are making another one let me know, I am always looking to learn more, they are excellent. Now on can complete the wiring. Its going a bit slow but I have time and hopefully in a couple of years my son can help.

Thank You - Matt