Things to Know About Replacing a Burned-out Fuse - Toyota Service Information To Know in Salem, OR

Modern cars feature more sophisticated electronics than ever before, and that means there are more fuses and relays to make it all work properly. You could experience all sorts of electrical problems if you've got a blown fuse or a bad relay. If the electronics in your car aren't working like theys should, checking the fuse box is a great place to start. Our service team has gathered these five tips that'll help you learn more about the fuse box on your car and what the fuses and relays do. If you need some expert help, stop by Capitol Toyota or just give us a call to speak with one of our friendly technicians.

Using a special fuse-puller, a tech has pulled out this fuse, showing that it's still intact.

5. Fuses & Relays -- What Are They?

In the fuse box on a modern car, you'll find a whole bunch of multi-colored electrical fuses and larger, plastic boxes called relays.

Fuses are included on all your car's various electrical circuits to protect components from surges of electricity. If too much current flows through the circuit, the fuse will blow -- interrupting the circuit and halting the flow of electricity, protecting the components further down the circuit.

Relays are remote switches that open or close an electrical circuit. For example, only a little electricity is needed for the headlight switch that turns your headlights on and off. When you turn the switch on, instead of sending power through the switch to the headlights directly, the switch activates a relay, sending a whole lot of power to the headlights.

The color of these fuses indicates their amperage rating.

4. Why Fuses Blow

Sometimes, a momentary surge of electricity could randomly cause a fuse to blow. Once the fuse is replaced, the circuit is restored. However, it's more likely that a blown fuse is caused by an electrical problem. It could be a faulty component drawing too much power, a short circuit or a ground fault.

3. Replacing Blown Fuses

If you've identified an electrical problem on your car, like a component that's stopped working such as wipers, lights, the horn, power windows and doors, etc., check the associated fuse first. You can find a fuse diagram on the lid of your car's fuse box and/or in your owner's manual.

Inside the fuse, a small strip of metal is designed to melt if the current through the fuse exceeds a certain amperage. If you look inside and the strip of metal is in one piece, the fuse hasn't blown. However, if the metal strip is broken, that's a blown fuse.

To replace a blown fuse, just find a new fuse of the same color and amperage and replace it in the correct slot. You'll often find spare fuses in the fuse box.

A technician installs a new fuse in this fuse box, complete with grey plastic relays.

2. Testing Relays

Most vehicles use a handful of identical relays for various systems. To test a relay and make sure it's working properly, you can borrow a relay from elsewhere on the car. For example, if your headlights aren't working, you could try unplugging the headlights relay and borrowing a matching relay from the windshield wipers. If the headlights work with the borrowed relay in place, you know the old relay was broken.

1. Further Diagnosis

Because fuses are designed to blow when a faulty component is drawing too much electricity, sometimes, replacing a blown fuse isn't enough to ultimately fix a problem on your car. In fact, it's likely that the replacement fuse will blow, too, if the underlying electrical issue has not been addressed.

With hundreds of feet of wire going through a modern car, identifying the source of electrical problems can be tricky -- especially without all the right tools. That's where the team at Capitol Toyota comes in! Our expert technicians have the experience and know-how to find the source of your car's electrical issue. Turn to the pros at the Capitol Toyota service center when you need help with your car's electronics.

Schedule service online at Capitol Toyota of Salem
Order parts online from Capitol Toyota of Salem


Capitol Toyota

783 Auto Group Avenue Ne
Directions Salem, OR 97301

  • Sales: 503-399-1011
  • Service: 503-399-1011
  • Parts: 503-399-1011