Virginia Auto Service

What Causes Your Car to Keep Blowing Fuses?

Every passenger vehicle has a fuse box. Fuses are electrical devices that are designed to stop circuits from being overloaded. When automotive fuses blow, they will cause problems with the functioning and accessories of your vehicle. If your car’s windshield wipers, power windows and locks, turn signals, or interior lights suddenly cease to function, then you may have a blown fuse on your hands.

What causes your car to keep blowing fuses?

If your car blows a fuse: Consult your car’s owner’s manual to find the location of the fuse box. The assigned circuit for each fuse should be shown in a diagram. Some fuses will easily come out by hand, while others might require the use of a pair of pliers. A blown fuse will be black on the inside with a melted metal ribbon, and the glass encasing might be cloudy. Visually inspect each fuse and replace faulty ones as needed.

Replacing faulty fuses in your vehicle is an easy fix, but there might be an underlying factor that causes them to keep blowing out. Here are the 2 most common reasons that your car keeps blowing fuses.

  • Your car has a short circuit. Automotive fuses are used to protect the electrical components and wiring system for your vehicle. A short in the electrical system will just cause a fuse to blow, rather than the wiring overheating or melting. A short is just a poor connection between two conductors that supply electricity, causing an electrical overload in the circuit. Fixing a short circuit is much easier than identifying the location of the problem. There are 3 typical causes of a short circuit in your car:
    • Fraying of the wire insulation. If one of the wires is frayed and becomes exposed, it can touch the metal frame or the ground, causing a short in the circuit. The wire might move around a lot and only occasionally come into contact with a surface, causing intermittent shorts. This is still enough to blow a fuse.
    • An electrical device is malfunctioning. Internal damage to your windshield wiper motor or power locking components can cause these systems to use more current flow than normal to keep working. This will overload the circuit causing it to short.
    • A conductor is being exposed to the elements. If there is a leak somewhere in your car, fluid could be wetting the wiring harness and connection points. A wet conductor can easily cause the circuit to short.
  • Improper fuse replacement. Fuses can keep blowing out if someone has replaced a blown fuse with one of higher amperage. There are a lot of different types of automotive fuses in both amperage and material. Your vehicle’s manual should contain a diagram showing the correct amperage rating for each fuse and the circuit that it is in. If you are unsure as to the amperage required for your car’s fuses, consult an automotive professional to be sure that the right fuse is being used in the right location.

If your car keeps blowing fuses, you need to get to the underlying cause of the problem. Replacing a fuse is an easy, cheap fix, but problems that keep causing fuses to blow can be much more complicated. For all of your auto service and repair needs in the Phoenix, Arizona area, you can trust the experts at Virginia Auto Service. Our ASE certified technicians have a reputation for doing the highest quality work and providing outstanding customer service. Just book an appointment online or give us a call at (602) 266-0200.