Vehicle window motors and regulators are designed to move the windows up and down without the effort of using a window crank. Since vehicles are becoming more complex, power windows are more common on vehicles today. There is a motor and regulator that is powered up when the ignition key is in and set to the accessory or on position. Most window motors do not have power to them without the key to the vehicle. This prevents the electric motor from activating with no one in the vehicle.
If the window motor or regulator assembly fails, the window will not move up or down when trying to operate the switch. The window will automatically drop down. If one window is stuck down, fumes from the vehicle’s exhaust system, rain, hail, or debris can enter the vehicle and cause problems.
- Allen wrench set
- Boxed end wrenches
- Cross tip screwdriver
- Electrical cleaner
- Needle nose pliers
- Nine-volt battery saver
- Protective gloves
- Ratchet with metric and standard sockets
- Razor blade
- Safety glasses
- Small hammer
- Test leads
- Torx bit set
- Wheel chocks
Part 1 of 2: Removing the window motor / regulator assembly
Step 1: Park your vehicle on a flat, hard surface. Make sure that the transmission is in park (for automatics) or in first gear (for manuals).
Step 2: Install a nine-volt battery saver into your cigarette lighter. This will keep your computer live and keep your settings current in the vehicle. If you do not have a nine-volt battery saver, you can complete the job without it; this just makes it easier.
Step 3: Open the vehicle’s hood and disconnect the battery. Take the ground cable off the battery’s negative terminal, disabling the power to the ignition system, window motor and regulator assembly.
- Note: It is important to protect your hands. Make sure to put on protective gloves prior to removing any battery terminals.
Step 4: Remove the window switch screws. Before removing the door panel, you need to remove the screws attaching the window switch to the door panel. If the window switch is unable to be detached, you may be able to disconnect the harness connectors under the door panel as you pull it off.
Step 5: Remove the door panel. Remove the door panel on the door with the faulty window motor and regulator. Also remove the clear plastic cover behind the door panel. You will need a razor blade to assist with removing the plastic cover.
- Note: The plastic is essential in forming a water barrier on the outside of the inner door panel because some water always gets inside the door during rainy days or at a car wash. Check that the two drain holes in the bottom of the door are clear, and that there is no buildup of debris in the bottom of the door.
Step 5: Remove the assembly mounting bolts. Locate the window motor and regulator inside the door. You will need to remove the four to six mounting bolts that secure the window regulator assembly to the door shell. You may have to remove the door speaker to gain access to the mounting bolts.
Step 6: Prevent the window from falling. If the window motor and regulator still works, hook up the switch to the window motor and raise the window all the way up.
If the window motor does not work, you will need to use a pry bar to push up the base assembly of the regulator to raise the window up. Use masking tape to secure the window to the door to prevent the window from falling.
Step 7: Remove the top mounting bolts. After the window is all the way up and secure, the top mounting bolts on the window regulator will be visible. Remove the window regulator bolts.
Step 8: Remove the assembly. Pull out the window motor and regulator assembly from the door. You will need to feed the wire harness attached to the window motor through the door.
Step 9: Clean the harness with electrical cleaner. Remove all moisture and debris from the connector for a strong connection.
Part 2 of 2: Installing the window motor / regulator assembly
Step 1: Install the new window motor and regulator assembly into the door. Feed the harness through the door. Install the mounting bolts to secure the window regulator to the window.
Step 2: Attach the assembly to the window. Remove the masking tape from the window. Slowly lower the window and window regulator assembly. Line up the mounting hole to the window regulator and the door shell.
Step 3: Reinstall the mounting bolts. Install the four to six mounting bolts to secure the window regulator assembly to the door shell.
- Note: If you had to remove the speaker in the door, make sure that you install the speaker and reattach any wires or harnesses to the speaker.
Step 4: Install the plastic covering back onto the door. If the plastic cover will not seal back onto the door, you can apply a small coat of clear silicone to the plastic. This will hold the plastic in place and keep out the moisture.
Step 5: Install the door panel back onto the door. Snap all of the door panel’s plastic tabs back into place. Replace any plastic tabs if they were broken off.
Step 6: Attach the harness to the window switch. Install the window switch back onto the door panel. Install the screws into the switch to secure it to the door panel.
- Note: If the switch could not be removed from the door panel, you will need to attach the harness to the switch as you install the door panel to the door.
Step 7: Reconnect the battery. Open the vehicle’s hood. Reconnect the ground cable back onto the battery’s negative terminal. Remove the nine-volt battery saver from the cigarette lighter if you used one. Tighten the battery clamp to ensure that the connection is good.
- Note: If you did not use a nine-volt battery saver, you will have to reset all of the settings in your vehicle, like your radio, electric seats, and electric mirrors.
Step 8: Test the new window motor. Turn the key to the accessory or run position. Operate the switch for the door window. Make sure that the window goes up and down correctly.
If your window will not go up or down after replacing the window motor and regulator assembly, then further inspection of the window motor and regulator assembly or the door wiring may be required. If the problem persists, you can get help from one of the certified mechanics at YourMechanic, who can replace the window motor and regulator assembly and diagnose any other problems.
This article originally appeared on YourMechanic.com as How to Replace a Car Window Motor/Window Regulator Assembly and was authored by Marvin Sunderland.