Thanks MRLdave. The track is Bachmann EZtrack and the frog is non-conductive, probably plastic. That being said, both rails conduct, no matter which way the turnout is thrown. That unfortunately means that I cannot leave a locomotive parked on the stub siding while another one is running around the outside oval. How could I change the turnout so that power is turned off to the siding when the switch is thrown to the main oval?