New to model trains. My son loves Thomas the Tank Engine, so I got out my old Tyco Train(Shattanooga Choo Choo 0-8-0). I put the track together and tested it. I get a current through the tracks and the power supply is functioning properly. When I put the train on the tracks nothing happens. If I put a direct current on the tender(motor) it works. The question is when I know there is current on the tracks and I know the train works, why won't the two work together?