My passenger side door lock inside the car barely moves with the power switches anymore. I had this problem before, then played around with the lock for about 10 minutes, and it opened and closed easily after that. Now I'm back to the same old problem, and playing with it isn't helping. I thought at first that maybe the switch or motor/actuator was weak, but even moving the lock by hand has a lot more resistance than the driver side. Did anyone else have this problem? I'm thinking something in the door could use some grease.

 

It could very well need some cleaning on the internal mechanisms. A lot of grime can build up over time and with the factory lube on it, dust will just stick to it. I had the same problem a year ago and took it apart. Cleaned some gunk out and installed component speakers.