1. Preparation:
* Safety First: Disconnect the negative battery terminal to prevent accidental shorts.
* Gather Tools: You'll likely need screwdrivers (Phillips and flathead), sockets (various sizes), possibly a ratchet and extensions, pliers, a trim removal tool (to avoid scratching the interior), and possibly a wiring diagram.
* Obtain Replacement Parts: Order the correct replacement latch assembly from a Ford dealership, auto parts store (like AutoZone, Advance Auto Parts, etc.), or an online retailer. Make sure it's the right part for your specific van's configuration (e.g., passenger side, driver's side). Getting the wrong part can waste your time.
* Interior Access: You'll need to remove interior panels to access the latch mechanism. The process varies depending on your van's trim level, but generally involves removing screws and carefully prying off panels.
2. Removing the Old Latch:
* Remove Interior Panel: Carefully remove the interior door panel. Start by removing any visible screws. Then, using a trim removal tool, gently pry the panel away from the door. There are usually clips holding it in place, so be cautious not to break them.
* Disconnect Wiring Harness: Unplug the electrical connector for the door lock actuator. Take a picture or note the wire colors and positions before disconnecting, in case you need to reassemble it.
* Remove Latch Assembly: This is the most variable step. The latch assembly is usually held in place by several screws and possibly bolts. You may need to remove the inner door handle mechanism as well. Again, your repair manual will be invaluable here. Pay close attention to how the parts are connected; take pictures as you disassemble it.
3. Installing the New Latch:
* Install New Latch Mechanism: Carefully install the new latch assembly, reversing the removal steps. Ensure all screws and bolts are tightened securely.
* Reconnect Wiring Harness: Connect the wiring harness to the new actuator, ensuring it's properly seated.
* Reinstall Interior Panel: Carefully reattach the interior door panel, making sure all clips are properly engaged.
4. Testing:
* Reconnect Battery: Reconnect the negative battery terminal.
* Test the Latch: Test the new latch by locking and unlocking the door using both the inside and outside handles and the key (if applicable).
Important Considerations:
* Repair Manual: A repair manual specific to your 1999 Ford E150 is highly recommended. It will show you detailed diagrams and instructions, saving you time and frustration.
* Patience: This is not a quick job. Take your time, be methodical, and don't rush.
* Professional Help: If you're uncomfortable working on your vehicle or are unsure about any step, consider taking it to a qualified mechanic.
Remember, this is a general guide. The specific steps may vary depending on the model and trim level of your van. Refer to a repair manual for detailed, model-specific instructions. Always prioritize safety!
