Non derail switches

Is it all switches or just one

All

MSP,

Looking at the wiring diagram I do not see any commonality of the non-derailing function between switches other than the common (black) track connection.  Are your switches wire differently?

Sometimes the small pieces used to trigger the non-derail function can touch.  I used a small piece of styrene to separate the two small rail sections.   Also a cut in the track can close. I fill cuts with styrene. 

You’ve lost a ground somewhere on the track. Check the ground wires running to all the outside rails. 

If they ALL stopped working at once somehow the ground wire between the track power transformer and the ground wire for the turnout machine transformer are no longer connected.  That is the only logical explanation.

John,

Here is a diagram with the train transformer and AIU added.  Since both are connected at the track, is a connection between the transformers really needed?

If you are using a DCS AIU unit, it is possible the ground wire going to the AIU switch position is not connected..  To expand, coming off the AIU you should have 3 wires for each switch.  One going to the left side and one to the right side, then a ground to the middle terminal of each AIU switch position.  (In my case I used one ground connection, then daisy chained all the "center" AIU connections for each switch, if that wire was to get disconnected then none of the switches would work.)  An easy test would be to test by shorting the two outside rails together at a switch, (simulating non-derail) and if the switch works, it is most probably the AIU ground wire.

If you are using Remote Control from the hand held remote, and have the push buttons installed, and the derail.  You should be able to test each option and find out which one is not functioning.  Then investigate which one is the problem.

Romiller and John c.   You got it thanks.    I had inadvertently loosed the wires from the trans former to the terminal block feeding the switches and when I put them back they  got reversed.    Simple fix.     Thanks again.