There are two relays, a on / off relay and a high / low speed relay.
You want to see the voltage input from the switch at the BCM and see it change every setting. The scan tool will tell you weather it wants the motor running or not. If the contacts in the motor were bad, the motor wouldn't run but the BCM would think it was. All it knows is the relay was actuated and weather the motor is parked or not.
There were two common issues, the switch and the park switch in the wiper motor. Usually when the park switch goes bad, when you are in intermittent mode, the wipers would move a few inches and stop, move a few inches and stop.