The underhood fuse box is typically located under the hood, often on the driver's side. It's a large black plastic box with numerous fuses and relays. This is the most likely candidate if you're looking for a central location for electrical components.
The body control module (BCM) is the computer that controls many of the vehicle's electrical functions. Its location varies slightly depending on the trim level and options, but it's often found under the dashboard on the driver's side, sometimes behind a panel. It's a smaller, usually black, sealed box. You'll need to consult your Expedition's repair manual for its precise location.
To find the specific location for your issue, you'll need to be more specific about what you're trying to access or diagnose. Knowing the electrical component or system you're working on would help narrow down the location. Consulting a repair manual specific to your 2003 Ford Expedition year and model is highly recommended.
