Standard Gauge 90 degree Crossover help needed

What kind of cross overs do you have? Maker? Approximate year of production? A picture would help.

The crossovers are MTH 10-4006 so current production.  It’s USA Track (if that matters).  I’m not home right now to provide a picture but I will later.

I would use black electrical tape to widen the space between the crossing tracks and the hot center rail.

One of your train wheels is shorting the center rail to either of outside rails.

A fat rail tread or out of gauge wheel-set may be the cause.

A less likely cause would be short from the weight of the train on the crossing wiring under the crossing track.

Try to find the exact spot and/or car causing the problem.

Look at the center of the crossover, there should be a circle with a slot in the center. Place a small coin or large screwdriver in the slot and turn it like a switch to a different position. You should feel it fall in to position. Try 90 degrees and if that doesn’t work try 180 degrees or it might be in between the two. This will change the electrical flow through the crossover. You will need a lock-on placed on both sides of the crossover since moving the switch will cut power to diverging route.  May or may not help.

With your track-plan the switch position should not have any affect, but if a center rail is loose and could short to the base of the crossing, that would cause a short.

Check all the center rail insulating papers/felts are in place and not loose or missing parts.

The base is wired to the outside rails so any contract to the center rails will be a short.

With power off, Push the engine thru the cross over. Look for wheels touching the center rail of the 90 degree part of the crossing.

Okay, thanks for everyone's input.  I slept on it and looked at it again this morning. 

First of all, I should have mentioned yesterday that I placed a lock-on on either side of the layout to make sure there is good power everywhere.  So I new that the MTH crossover design with that little plastic wheel shouldn't present a problem.  I tested with a meter and have 18+ volts on every section of track.  That said, I just couldn't leave that center hub wheel alone.  I started spinning one of them with a coin.  It promptly broke off .  That's not a feature for me anyway so I'll just glue it in place and forget about it.  Cheap garbage.

Anyway, I did some testing and sure enough, the problem was the engine driver wheels contacting the center rail when it went through the crossover.  I tested with both a #9E and a 390E (both MTH repros, by the way).  Interestingly, rolling stock wouldn't trigger it.  First I tested a freight car and a passenger car.  Neither one caused a short.  The engines did everytime.  So I guess the extra weight over the drive wheels and their size/shape was just enough to contact the opposing center rail.  The last time I tried it, it actually sparked and stopped dead right on top so it was very obvious.

I placed a small bit of electricians tape over all 4 sides and the problem is solved.  After I break down this Christmas layout, I will permanently fix the problem.  I'll use a Dremel to grind off an 1/8" from each center rail.

Thanks everyone.  The layout is much more interesting with the crossovers.  I really didn't want to eliminate them.