All is well in River City!! I‘m a little embarrassed to report this but since I am a happy camper I’m making this post. Hopefully it might serve as a lesson to some other novice along the way. First of all, I really appreciate the input form all of you and I thank you for taking the time to offer your insight and suggestions.
Let me start with the fact that I had unhooked all electrical power to the layout in January because I sent my TIU in for a system upgrade. I had long planned to reorganize my power station and this was the opportunity to do so. I have several transformers supplying power to my layout, MTH Z-4000, Lionel V-150 & 1033 plus several plug in DC power adapters for LED lighting, Tortoise switch machines and track signals. My short term memory failed to remember that the DZ1000 switch machines were getting power from the fixed 14v terminal of the Z-4000 which provided a common ground and center rail power. I had rearranged the placement of my transformers when I re-powered. After spending time checking & rechecking all my wires and terminals connections to the DZ1000s, the light bulb in my head went on and I realized why the switches worked only with the selector buttons but not with the isolated contact. I was using the wrong transformer and the isolated section was not receiving power! Now the selector buttons use the fixed power source of the Z-4k to activate the switch and the non-derailing rails uses track power supplied by the Z-4K to activate the switch and both use the transformers common ground. Once this was understood and corrected, everything works perfect! Love it when a problem finds a solution!!!!!!
Double Cheers!!!! Dave