a multimeter would be safer than just a test light and will tell you more if you can use that instead. I believe the regulator and motor are in the same unit (i.e. a regulated motor). and yes they should be on the same fuse so that's prolly not it. you can always disconnect the motor/regulator from the rest of the system (unplug it) and hook a 12volt drill batter up to the motor and see if it spins. best bet is it's either the motor or the switch.
did that window just stop altogether (work one day then nothing the next) or did it start acting weird before it died. like it it went down, but didn't want to come back up or worked off and on with holding the switch?
first option is most likely motor, second is the switch.
2010 Volvo C70
2011 Harley FLHTK
Midwest Crew #22