The wiring circuits in your vehicle are protected from short circuits by fuses, circuit breakers and fusible thermal links in the wiring itself. 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 correct size.
If you ever have a problem on the road and don't have a spare fuse, you can borrow one. Just pick some feature of your vehicle that you can get along without - like the radio or air conditioner - and use its fuse, if it is of the value you need. Replace it as soon as you can.
Before replacing a fuse, turn every electrical switch off.