inside the door panel
A motor from a 1991 Oldsmobile will fit into a 1996 Oldsmobile Delta 88. The motor mounts will need to be changed.
In the engine compartment. Center of the firewall behind the engine.
have someone check the wiring of the window control panel, if its not that, its your window motor, for a '90 a used motor from a junk yard probably wouldn't be more than 30 bucks
fuse #5 on the relay panel on firewall left and above blower motor.
break the window
Behind the driver, under the frame.
To install a window in an '88 Oldsmobile Delta 88 two-door, start by removing the door panel to access the window mechanism. Carefully detach the old window by removing any screws or clips holding it in place. Position the new window into the track, ensuring it aligns properly, and reattach the window regulator and any necessary components. Finally, reassemble the door panel and test the window's operation for proper functionality.
Directly behind the engine, on the middle of the firewall.
To replace the window motor and housing on a 1989 Oldsmobile 88 Royal, first, remove the door panel by unscrewing any fasteners and gently prying it off to access the internal components. Disconnect the electrical connector from the old window motor, then remove the mounting bolts securing the motor and housing to the door. Replace the old motor and housing with the new unit, secure it with bolts, and reconnect the electrical connector before reassembling the door panel. Finally, test the window operation to ensure everything is functioning correctly.
Check fuses Check for loose connection in fuse block
Hemmings Motor News.com
under the hood on the fire wall.