Bill, if you isolate all 4 center rails you will have no power through the switches. Using auxiliary only powers the switch motors. If you have to isolate all 4 rails you will need to bring a power line directly from the track power supply to the center rail at the junction of the two back to back switches.
Thank you Danr. I am using all 4 extensions (2 per turnout) and have removed the jumper, and have confirmed isolation. Control power is auxiliary (connected from mainline to the aux control input with track jumper removed. Problem is center rail power which is removed due to isolation. I soldered train power to center rail (on the retainer that is on underside of turnout after confirming electrical integrity to the center rail and I confirmed that center rail was hot on both turnouts -- it is, as they are connected back to back by the rail joiner. Train powers through first switch and stops on second one. I quickly checked voltage and it is present on rail. I did not give too many details because I did not want to "lead" any of the replies, because the situation made no electrical sense to me. I was interrupted by layout visitors and had to quit, but I will check center roller on loco versus switch transition to be sure it remains in contact. I did not check that, because it seemed logical that loco passed through one switch so should pass through the next one. I will be on location later this week or early next week and will check further and let you guys know. Meantime, any suggestions are welcome.