Fuses

Fuses are important in that they protect electrical circuits from overloading and short circuits. Nine times out of ten when you have to replace a fuse, something is wrong. If a new fuse blows as soon as you put it in, you have an electrical problem that needs fixing. Never install a fuse of a higher rating than the one installed. Doing so could result in damage to the electrical system.

Fuses are pretty cut and dried. All modern cars use the same type of fuse. They are plastic and come in different colors corresponding to their amp rating. They come in different sizes, from a "Mini-fuse" to a "Maxi-fuse". These fuses are clear so you can tell at a glance if the fuse is blown or not. Sometimes a fuse will wear out and the only way to tell, accurately, if the fuse is good is with an ohmmeter. Since these fuses are small, there is usually a fuse-pulling tool in the fuse box. This tool grips the top of the fuse and allows you to pull it out for inspection or replacement.

Older cars use a glass tube type of fuse. These are a clear glass tube with metal end caps. These also come in different ratings that are stamped on one of the metal end caps. Like the plastic fuses, you can see at a glance if they are burnt out. And, also like the plastic fuses, they wear out and an ohmmeter is required for testing.

Another type that was used on older European cars was a plastic fuse that had the fuse material on the outside. These were unreliable since the fuse material was exposed to air and in time became corroded and would break. These aren't used any more in favor of the newer plastic fuses.

It is always a good idea to check your lights on a routine basis. It only takes a few minutes and it could save you a ticket.