Presumably this is an American Flyer locomotive. The first thing to do is check the wiring. If you are powering up the motor directly, first disconnect the harness to the tender. Power to the motor from one transformer lead goes to one brush connection. The other brush connection gets connected via a jumper wire to one field winding. The other field winding goes to ground, where the other transformer wire is also connected.
Power up the transformer, and if everything is installed and wired properly, the motor should run. If it does, reverse the wires to the brushes and the motor should run in the opposite direction.
If the motor does not run, without power, try and turn the armature by hand. It should turn and slowly turn the wheels. Also recheck all the connections.
Larry thank you very much for.your answers still wont run I put power straight to the bushing the armature gets power but when I hand turn the amature I get a spark but the armature won't turn over I tried switching the power wires the armature won't still turn over the armature tpurns freely by hand replaced brushes springs and armature if you have any ideas what im doing wrong I would surely appreciate yiur help very much thank you
May you and your family stay safe from the invisible monster god bless