To find the correct fuse:
1. Consult your owner's manual: This is the most reliable source. It will have a diagram showing the fuse box layout and what each fuse controls.
2. Check the fuse box diagrams: These are usually located inside the fuse box itself, often on the inside of the cover.
Without your owner's manual, I can't give you the exact fuse number. Look for a fuse labeled "Power Outlet," "Accessory," "12V Outlet," or something similar. The amperage is likely to be between 10 and 15 amps.