For 1990-2009 cars

The wiring circuits in the vehicle are protected from short circuits by a combination of J-Case fuses, mini-fuses and circuit breakers. This greatly reduces the chance of fires caused by electrical problems.

Look at the silver-colored band inside the fuse. If the band is broken or melted, replace the fuse. Be sure you replace a bad fuse with a new one of the identical size and rating.

If you ever have a problem on the road and do not have a spare fuse, you can borrow one that has the same amperage. Just pick some feature of the vehicle that you can get along without - like the radio or cigarette lighter - and use its fuse, if it is the correct amperage. Replace it as soon as you can.