1987 Oldsmobile 88 Delta Royale B.

By "no power", do you mean the window doesn't work or there's no electrical power getting to the switch? When a window doesn't work in either direction, it is usually caused by broken wires between the door hinges. When it runs slowly in both directions, suspect the thermal cutout inside the motor. When it runs slowly in one direction but faster the other way, suspect tar and bug juice on the rubber channels. When it runs normally for a little way, then stops, suspect frayed cables or broken plastic pulleys on the regulator. When it only goes one way, it's a bad switch. For the passenger windows, either the passenger or the driver's switch could be at fault, regardless of which one doesn't work.

Pull the boot and tape off the wires between the door hinges. It's almost certain you're going to find some wires that are broken. If you do, I'll tell you how I repair them.