* Under the main fuse box cover: Often, the relay box is located *under* the main fuse box cover. The fuse box itself is typically situated on the driver's side fender well, near the battery. You may need to remove the main fuse box cover to access the relays.
* Separate box near the battery: In some models, there's a separate smaller box near the battery that houses additional relays.
To find it with certainty:
1. Consult your owner's manual: This is the best resource. It will show a diagram of your vehicle's fuse and relay box locations.
2. Look for labels: Once you're under the hood, look for boxes that are clearly labeled "Relays," "Fuse Box," or have a diagram indicating various components.
3. Online resources: Search online for "2003 Ford Focus relay box location [body style]" (e.g., "2003 Ford Focus relay box location sedan"). You'll find images and possibly videos showing the location.
Remember to be cautious when working near the battery and electrical components. Disconnect the battery's negative terminal if you're doing any significant work.