You'll need to identify the primary switches that send power to the score motor. On the schematic, look for the score motor icon and the circuit connected to the score motor. When the score motor is running, check which relay switches are closed in the circuit leading to the score motor.

It sounds like the ball is keeping the outhole switch closed, but the ball isn't being kicked to the shooter lane. When you place the ball in the outhole, will it kick the ball through the trough to the shooter lane?