I think Mark meant for you to substitute the motor with the bulb as its a visual aid to current consumption and a lot easier to work with than moving a motor around the vehicle to do your testing!
As for moving it along the wiring this will prove and pinpoint the location of a possible short or open in the supply, i.e if the bulb illuminates one side of a plug connector and not the other then obviously you have an issue within or at that connector. Apologies if you were aware of this and just misunderstood Marks advice