To find it, you'll need to:
1. Consult your owner's manual: This is the most reliable source. The manual will have a fuse box diagram showing which fuse controls what. Look for a fuse labeled "instrument panel illumination," "dashboard lights," or something similar.
2. Check both fuse boxes: If you can't find it in one fuse box, check the other. The engine compartment fuse box often contains higher amperage fuses, while the interior fuse box usually handles smaller circuits like lights.
3. Look for a diagram inside the fuse box cover: Often, the fuse box cover itself will have a diagram showing which fuse controls which circuit.
Without your specific Mondeo's trim level and the owner's manual, I cannot give a more precise location. If you don't have the owner's manual, you might be able to find a PDF version online by searching for "2001 Ford Mondeo owner's manual [your trim level]".