Everyone has experienced a power window that freezes in a certain position, chatters, slips in its guide or falls down inside the window well. In many cases, if it's not the switch, wiring or motor that drives the window regulator, it's the window regulator itself. Window regulators are the mechanical gizmos inside your car doors that receive rotor power from the motor and translate it to up-and-down motion. It does this with levers and arms that work in scissor fashion to lift or lower the window smoothly and evenly. These complex linkage arms and levers are lubricated, and they can become filled with gunk or they can completely dry out, causing a regulator to stop functioning. An industrious vehicle owner can lubricate a window regulator herself, restoring new life to her car's window.
Set the vehicle in park or neutral with the emergency brake set and the engine off. Disconnect the negative battery cable clamp from the negative battery post. Open the door with the malfunctioning window regulator. Prop the door wide open if necessary by wedging a block of wood in the door seam.
Use the appropriate-size Phillips screwdriver to loosen the screws on the armrest. Some armrests have plastic access caps that you can pop out with a slot screwdriver. If the armrest has a window control built into it, you may remove the top screws in it and pull it out far enough to disconnect the electrical jack, or wait to disconnect the jack once the panel has been removed.
Use the appropriate socket to loosen the door panel mounting bolts through the open space where the armrest was removed. There might be two or three in this location. Locate the door handle and remove the screws to the plastic shield. If another door panel mounting bolt sits inside the shield seat, remove it with a socket.
Pry the door panel removal tool, which has a U-shaped head, between the seam of the door panel and the steel door frame. Wedge the head in and pull back on the handle to snap each spring clip free. Work the tool all the way around the perimeter of the door panel until all of the spring clips have popped out of the mounting holes. Do not lose the clips. Pick them up if they fall and reinstall them back into the door panel guides when you have taken the door panel off. Pull the door panel back from the door frame far enough to disconnect the electrical jack that goes to the armrest control panel.
Pull down the top of the plastic liner (weather guard) from the top and both sides of the steel frame. Leave the bottom of the liner hanging. Look inside the door frame and note the long linkage arms that stretch from side to side, possessing a scissor-type construction. All the linkages, arms and pivot point compose the parts of the power window regulator system. Clean the regulator parts with carburettor cleaner and a small brush, removing all caked-on grease and oil. Wipe dry with clean rags.
Take a spray can of white grease and attach the long directional nozzle on it. Position the nozzle at the appropriate angles to spray grease on the regulator pivot points, front and backside. Note where the levers slide against their travel points. Spray grease on these (shiny) spots. Locate the window motor, a small, round, black, canlike object, and spray grease into its gear mesh and on the half-moon shaped gear that has teeth on it. You can use a small basting brush and canned lithium grease as an alternate method of lubricating the window regulator. For hard-to-reach joints, dab your finger in the grease and lubricate the joints and gears by feel.
Raise the plastic weather-guard sheet and push it back onto its glue bead. Using palm pressure will help to reseal it. Lift the door panel up into position and reconnect the electrical jack to the armrest window control panel. Bend down low and align the spring clips on the door panel with their mounting holes in the frame. Once aligned, push the door panel inward hard enough with your palm to seat one clip. Then do another. Pop all the clips back into position, working all the way around the panel.
Use the appropriate socket to install and tighten the door panel bolts through the armrest hole. Reattach the armrest and tighten the mounting screws with a Phillips screwdriver. Replace the bolt through the door handle hole and tighten it. Put the plastic door handle shield back into position and tighten the Phillips screws. Reconnect the negative battery cable clamp to the negative post. Test the window operation, raising and lowering it several times to work the lubrication grease into place.