Vehicle Electrical System: What's A Fuse? | Sun Devil Auto

Your Car’s Fuse Box Has All the Answers

You’re driving down the 101 listening to your radio, lightly tapping your fingers to the beat, when suddenly your radio just quits. You push the ‘on’ button with no response. Perhaps you also notice that the dome light no longer turns on when you open doors. Before panicking and assuming your battery is losing its charge, or your vehicle’s electrical system has malfunctioned, check your fuses. Fuses are used to limit the electrical current flowing through wires to protect certain components. In your car, the fuse box is used to protect the electronics within your vehicle. Car fuse box repair may be necessary when your car temporarily loses functionality of certain electrical components as a result of blown fuses.vehicle fuse box

What is a Fuse?

Fuses come in all shapes, sizes, and colors and are used to even out and reduce the electrical current that flows through wires to prevent damaging electronics from too much electricity. Often, fuses come in a rectangular or tube-like shape. A rectangular fuse is composed of two push in-connectors linked by a fuse wire in a protective covering, typically made of plastic, which will burn through or blow, as it is often referred to, when overloaded. Tube fuses have a similar likeness to a fluorescent light bulb, on a much smaller scale, where the tube portion is long and at either end is a protective housing made of glass between them. Running between the metal ends and protected by the glass, is a thin fuse wire which burns through and will blow when overloaded.

Without fuses, a large, overloaded electrical current could cause the wires to overheat, melt the insulation, and could result in fire. A high current to any component equals instant failure, therefore, the fuse ensures that current stays at a reasonable level for the component to continue to function. Still, if the current is too high, the fuse will blow. Drivers will notice trouble with fuses when the vehicle’s windshield wipers, headlights, interior lights, seat warmers, or radio do not function. In some cases, the vehicle may also have difficulty starting.

What is a Fuse Box?

Most vehicles are equipped with two fuse boxes. One is located in the engine compartment and is used to protect engine components such as the cooling system, anti-lock brake pump, and the engine control unit. The other is often found in the cabin area in or under the dashboard, on the driver’s side to protect interior electrical items. The fuse box houses a variety of fuses and relays in one convenient place, protected from outside elements. Car fuse box replacement isn’t often necessary unless the vehicle has experienced severe physical damage or electrical problems.

Replacing Fuses

Refer to your owner’s manual to locate your vehicle’s fuse box(es). Not only will your manual clue you in to where the fuse box is located, a diagram will also indicate the designated fuse for each component. This diagram is quite useful in determining which fuse has blown. It is highly recommended that when replacing fuses, you use only Original Equipment Manufacture and equal amps. Do not replace a 10-amp fuse with a 30-amp fuse. The 10-amp is designed to blow at a lower current rate, whereas a 30-amp would allow for a higher current to pass through. Using a higher current to pass through than what is recommended, could be detrimental to the component.

Though most fuse boxes will last the lifetime of the vehicle, there is a possibility that it may require replacement if the terminals, where fuses are plugged into, become overheated and cause the plastic to melt.

Fuses are essentially the guardians of your vehicle’s electrical components. Relays within the fuse panel help to protect the driver by keeping the high voltage supply away from drive switches. The fuse box houses the fuses and relays to prevent damage from water, weather, and other driving conditions. Vehicle fuse boxes often fail because of overheating for several reasons including added aftermarket electrical accessories or components or incorrectly sized connections and wires by the manufacturer, which typically results in a vehicle recalls.

 

Any time you are working with your vehicle’s electrical system, use extreme caution. Mishandling the fuse box or fuses could cause irreversible damage to the vehicle or harm to yourself.