means just that.The fuse is "in-line" of the hot(red)wire. To find the wires that lead to the outlet you will have to remove the outlet or more than likely, the whole nav panel. This is not as hard as it sounds, but before you remove the panel, turn the battery switch to "off" and make sure you are not pluged into shore power.You should find a red and a black wire leading to the outlet. If there is an in-line fuse,you will see it's holder on the red wire. Push and twist to open and remove the fuse. If it is good, it will have a thin wire or metal visible through the glass. If no element is visible, the fuse is blown.Make sure you replace the fuse with one of the same size, volt and amp or less. NEVER MORE,unless you are a piromaniac. Good Luck, Bob