Electrical gremlins

It could possibly be the wheels are touching both insulated rails at the same time.  Are those rails real close to each other?  Switch motor itself may have in issue.  RICH

If the turnouts are the same, I would switch two of them. If the problem moves with the turnout, there is an issue with the turnout, otherwise problem is in the wiring/relay.

If they are Ross, check the the non derail rails where the spikes attach them. Sometimes two spikes will be touching each other holding down both rails. If they are then remove the spike.

Picture of what Rod mentioned.  The small piece of white styrene was required to isolate the two short input rails.

I also use styrene where the short rails terminate.

Rod,  Great pictures and tremendous explanation!  I've experienced this numerous times.

Mike CT posted:

Picture of what Rod mentioned.  The small piece of white styrene was required to isolate the two short input rails.

I also use styrene where the short rails terminate.

I used the plastic joining pins from ROSS ... resistance meter indicates they are isolated.  It's the turnout where the newer upper level joins the existing main line.  The two are on different circuits from the Z-4000 and the problem turnout does not have a relay; just the two non-derailing wires and the left, right, and 14V ac lines.  The other turnouts on the upper level, all three of which have relays, work correctly with lights, BUT I had to join the ground circuits, the common, for both the turn out and the track before it would work with non-derailing hooked up.

I'll go over it today looking specifically for the situation with the spikes you reference.

Thank you!!