98 grand voyager window motor issues

[Adasm]

Ok, i've been reading alot of threads on this subject and I just wanted to post my own with the issues i've found with mine: my passenger window wont move anymore, but it'll move maybe about a 1/4 of an inch if i'm lucky then not move at all. I have done thus so far:
driver's side is fine so i swapped the brushes, armature and capacitor from the working side into the passenger side motor and still get the same result. So i've confirmed that the capacitor is fine, the armature is fine and the brushes are fine. What else could cause the motor to not engage? i've multimetered the hell out of this thing and have found power all across the whole assembly? what am I not seeing that can cause this motor to not move? and it's definitely not a stuck regulator because I can manually turn the armature with my fingertips and move the window fully down and back up again. Any ideas???

[Adasm]

Wow, not even an idea whatsoever?

[RIP]

Nope. In the half dozen or so power window problems I've worked, I've always changed a window regulator and it's always fixed the problem. Never taken the time to disect it to your degree. Try spraying a little silicone lube into the side window guides.

[Adasm]

Yeah, i know it's a crapshoot trying to dissect it, but it's just a nagging problem as to why it doesn't work. I'm usually okay with just replacing something if it's broken, but i'd love to know exactly why this is not working. But, i'll probably just end up changing it soon enough.