1. Preparation:
* Safety First: Disconnect the negative battery terminal before starting any work on the electrical system. This prevents accidental shorts and shocks.
* Gather Tools: You'll likely need a variety of tools, including sockets (various sizes), wrenches, screwdrivers (Phillips and flathead), pliers, and possibly a ratchet. A shop manual will list the specific tools.
* Obtain Parts: Ensure you have the correct replacement wiper motor for your 1989 Ford Expedition. Using the wrong part will lead to frustration and potential damage. Double-check the part number against your vehicle's information.
* Work Area: Work in a clean, well-lit area. Consider using jack stands to safely lift the vehicle if needed for better access.
2. Accessing the Wiper Motor:
* Under the Hood: The wiper motor is usually located under the hood, near the base of the windshield. It's often hidden behind the cowl (the metal panel under the windshield).
* Removal of Cowl: This is usually the most challenging part. You may need to remove various clips, screws, and possibly even the wiper arms themselves. The repair manual will show you the exact steps and locations of fasteners.
* Disconnect Electrical Connections: Once you have access to the motor, carefully disconnect the electrical connectors. Take pictures or make notes to remember how they go back together.
3. Removing the Old Wiper Motor:
* Bolts and Fasteners: The wiper motor is usually secured by several bolts. Carefully remove these bolts, taking note of their locations and lengths.
* Removal: Once the bolts are out, gently remove the old wiper motor. It may be slightly difficult due to its location and potential rust or corrosion.
4. Installing the New Wiper Motor:
* Installation: Carefully align the new wiper motor with the mounting holes.
* Bolts and Fasteners: Secure the new motor with the bolts you removed earlier. Tighten them securely but avoid over-tightening.
* Reconnect Electrical Connections: Carefully reconnect the electrical connectors, making sure they're firmly seated and match the diagram or pictures you took earlier.
5. Reassembly:
* Replace Cowl: Carefully reassemble the cowl, ensuring all clips and screws are properly fastened.
* Reconnect Wiper Arms: If you removed them, reattach the wiper arms.
* Test the System: Reconnect the battery terminal. Turn on the ignition and test the wipers to ensure they work correctly. If they don't work, double-check all connections.
Important Considerations:
* Repair Manual: A repair manual specific to your 1989 Ford Expedition is crucial. It will provide detailed instructions, diagrams, and torque specifications.
* Rust and Corrosion: Due to the age of your vehicle, you may encounter rust and corrosion around the wiper motor. Use penetrating oil to help loosen things up.
* Patience: This is not a quick job. Be patient and methodical to avoid damage.
* Seek Professional Help: If you're not comfortable working on your vehicle's electrical system or are unsure about any step, consider taking it to a qualified mechanic.
Remember, this is a general outline. Always consult a repair manual for your specific vehicle to ensure you have the correct procedure. Improper installation can lead to further damage or even injury.
