hello,
Does anyone know how to fix the power windows? When I open the windows on the passenger side, it only goes down halfway then I hear this sound before it stop. Could someone please help me solve the problem. Thank you.

 

Could you get a video of it happening? Or describe the sound/events more specifically?

 

If you remove the interior door panel, leaving the switch connected, and operate the window, you will see the problem. Something is physically obstructing the path of the downward glide of the glass/track - or the motor itself is bad. For a Z32, replacement motors ought to be available.

When removing the door panel, save the screws and be careful with the snap-on plastic panel clips at the perimeter. They are carefully aligned and break easily if popped on an angle. Nissan mechs had special tools for this, tools you probably don't have there. Take your time.