I was successful in isolating the crossover between the two tracks, even the switches work. It's not easy, Len was right, you have to take it completely apart and remove the copper bands connecting all the tracks. There is a dead spot between the frogs which the train runs through then picks up power from the other controler. Next time I feel like taking it apart I'll cut the tracks in the middle and solder jumpers to shorten the dead spot. But it works! My granddaughter is going to be happy. It is confusing to control with the switches and the right direction, she'll crash a couple times but she'll get it.