G'day! You're in the kitchen, you've got the toaster and the kettle going at once, and pop – the power goes out. Or you're in the ute, you flick the switch for your driving lights, and... nothing.

Sounds like you've blown a fuse. A fuse is a fair dinkum little hero; it's a small safety device designed to be the "weak link" in a circuit. It sacrifices itself (it "blows") to stop an overload or short circuit from knackering your expensive gear or, worse, starting a fire.

But how to tell if a fuse is blown? Well, mate, that depends entirely on what kind of fuse you're looking at.

The Big One: The Old Ceramic House Fuse (A Serious Safety Warning!)

Righto, let's get the serious one out of the way first. If your house is an older one (pre-1990s), you might not have a modern switchboard with flicky switches. You might have an old ceramic "fuse box."

This is a 240-volt system and is extremely dangerous. Don't be a galah – this is NOT a DIY-friendly area.

Symptom: The power in one part of your house (like the kitchen or the lights) is completely dead.

How a Pro Would Check:

1. Safety First: They would turn off the main power switch for the whole house.
2. Pull the Fuse: They'd carefully pull out the ceramic fuse holder for the circuit that's dead.
3. Visual Check: Inside that holder is a thin piece of fuse wire. If that wire is broken, melted, or if there's a black, sooty mark on the ceramic, she's blown, mate.

The Big "But": If your old ceramic fuses keep blowing, it's a sign your wiring is overloaded or has a fault. It is fair dinkum time to call a licensed electrician. Do NOT be tempted to whack a bigger fuse wire or, worse, a nail in there. That's a one-way ticket to a house fire. A pro will recommend upgrading your board to a modern, safe switchboard with resettable breakers.

The Common One: The Car Blade Fuse (12V DIY)

This is the one you'll most likely be dealing with. Your car's radio is dead, or the indicators have stopped working. This is a safe, low-voltage (12V) job you can do yourself.

How to Check:

1. Turn the car off. Find your car's fuse box (check your owner's manual, mate – it's usually under the dash or in the engine bay).
2. Pop the Cover. There's usually a little map on the inside of the lid. Find the fuse for the thing that's knackered.
3. Pull the Fuse. Use the little plastic fuse-puller tool (often in the fuse box) to yank the fuse out.
4. Hold it to the Light. This is the easiest way. Look at the little 'S' shaped metal link inside the coloured plastic. If that link is broken or has a tiny black mark on it, it's blown.
5. Replace it with a new fuse of the exact same amp rating.

The Fiddly One: The Glass or Cartridge Fuse (Plugs & Appliances)

You'll find these little glass tubes inside some appliance plugs or deep in the guts of electronic gear.

Method 1: The Visual Squiz

Sometimes, you get lucky. You can hold the glass fuse up to the light and see the tiny filament wire that runs through the middle. If that wire is broken or missing, she's blown. If the glass is all black and sooty, she's really blown.

Method 2: The 'Can't Fail' Multimeter Test

This is the pro way and the only way to be 100% certain, especially if you can't see inside the fuse.

1. Safety First: Make sure the device is unplugged and the fuse is taken out of its holder.
2. Set Your Multimeter: Get your multimeter and set it to the "Continuity" setting (the one that looks like a sound wave or a diode) or the lowest "Ohms" (Ω) resistance setting.
3. Touch the Ends: Touch one probe to one metal end cap of the fuse, and the other probe to the other end.
4. Listen for the Beep:
   • If it BEEPS (or your Ohms reading drops to near zero), the fuse is GOOD. The path is complete.
   • If it stays SILENT (or your meter reads "O.L." / "Open Loop" / "1"), the fuse is BLOWN. The path is broken. Too easy.

A Professional Job Needs Professional Gear

Knowing how to tell if a fuse is blown is a top skill. But for your home's 240V system, a blown fuse is a serious warning. It's a sign it's time to upgrade to modern, safe circuit breakers.

When you get a licensed electrician in for that upgrade, they'll be using high-quality, compliant components sourced from a trusted electrical wholesaler. As one of Australia's most comprehensive electrical wholesaler and supplier networks, Schnap Electric Products stocks the lot. From the modern, life-saving RCBOs and circuit breakers to replace those old fuses, to every other compliant component a qualified professional needs. For a safe upgrade that's built to last, the pros rely on a supplier like Schnap Electric.