Need Help With Information on Lionel Train Set

[Iron Horseman]

The loco stalls as it passes over the turnout when the switch is thrown. It works when the points allow the train to proceed straight but not into the spur track. Does that make sense?

Yes, what you have said makes sense. I believe there is a flat metal contact inside the turnout. My guess the sliding "finger" is not making that contact in the diverging position. Some of the turnouts are riveted but others have screws one can take out to access the internals.