Why Does My Motorcycle Keep Blowing the Ignition Fuse?

Why Does My Motorcycle Keep Blowing the Ignition Fuse?

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Why Does My Motorcycle Keep Blowing the Ignition Fuse?

An ignition fuse protects the wiring of an ignition system. Since engine coils require 30,000 volts, an ignition fuse guards against electric arcs from shorting the electrical circuit.

It also minimizes resistance in the wires and prevents voltage spikes from adversely affecting other systems that are sensitive to high-voltage surges.

The blowing of the ignition fuse in your motorcycle can have a few possible causes. Here are some of the most common ones:

Short circuit in the wiring: A short circuit can cause a high current to flow through the ignition circuit, blowing a fuse. This can be caused by damaged or frayed wiring, broken connectors, or exposed wires. To fix this, connect the positive (usually red) and negative (usually black) wires connecting the battery to the fuse box tightly.

Loose connections or corroded connections can cause a short circuit in the wiring.

Other Causes:

Defect In The Ignition System

A defective ignition coil can cause a short circuit in the wiring and blow a fuse. A defective spark plug or coil wire can cause an arc between the plug and the cylinder head and blow out other ignition system components.

Short Circuit in The Battery Or Wiring To The Battery

A short circuit between the positive and negative terminals of the battery can cause a high current to flow through the wiring, fuse box, and ignition system, blowing out components in all these areas.

Also, frayed or damaged wiring between the voltage regulator on the handlebars and the regulator/rectifier on its bracket can cause a short circuit and cause the regulator/rectifier to overheat.

This can result in melted plastic housing.

Faulty Ignition Switch or Wiring

The ignition switch and wiring can be faulty. If the key is in the “ON” position but won’t turn over the engine, the wires are broken, frayed, not fully connected, or corrosion has occurred.

Why Does My Motorcycle Keep Blowing the Ignition Fuse?

The breakage of wires due to a corrosion buildup can cause a short circuit to occur when you make a connection.

How Do You Fix a Motorcycle Fuse That Keeps Blowing?

FactorHow to Fix
Faulty BatteryCheck the starter with a voltmeter, Check the alternator with a voltmeter.
Check battery cables for corrosion and make sure they’re tight.
Faulty Regulator/RectifierReplace what’s causing the problem.
Faulty CoilReplace as necessary
Fuse Or Wiring IssueCheck wiring, fuses, Dirty connectors can cause a fuse to blow or a hot wire to burn through the insulation.

Corrosion on the connectors can cause a fuse to blow or a hot wire to burn through the insulation,Cracked or broken wiring can cause a fuse to blow.

Bad connections at the battery can cause a fuse to blow.
OverloadingIf your bike has a lot of accessories (high output stereo, heated grips, fog lights) and you’re using a smaller fuse to protect them, replace the fuse with one that’s rated for more amps.
Poor ConnectionsClean the connectors and make sure there aren’t points in the wiring where the insulation is worn through.

Make sure wire nuts are put on correctly and that each wire is put into the correct slot on the connector.

Replace any connectors if they’re damaged or rusted.

What Are the Symptoms Of A Faulty Motorcycle Fuse?

1. Intermittent Power Loss

One major symptom of a faulty motorcycle fuse is intermittent power loss.

This can happen when you’re riding your bike, or it may be intermittent and only occur in certain parts of the operation or during certain conditions.

This could happen when driving on hills, for example, where your speed drops abruptly as the engine works harder.

Over time, this drop-off can cause issues with fuel delivery and other systems that depend on consistent power from the battery.

2. Rapidly Flashing Tail Lights

Another symptom of a faulty fuse is when the tail lights on your bike flash rapidly. This may result from a shorted fuse, but it’s also possible that the system has failed, and you have no power.

3. Blinking Headlights

Another symptom of a faulty fuse is when you see your headlight blinking steadily or in jolts, even as you’re getting ready to move into position for the night or get off at a stop sign.

Any fault in your electrical system will cause this, but it can also mean that your contact breaker has failed or there’s a shortage in your wiring.

4. Constant Engine Noise

Such noise occurs because of faulty ignition or other similar problem that results in power from the battery not reaching your motorcycle’s electric components.

While it could also mean that you’ve got a lousy contact breaker or you’ve got problems with your wiring.

It’s best to have it checked right away because if this is due to an ignition problem, you won’t be able to start your bike even after the faulty fuse is replaced.

What Does It Mean When a Fuse Keeps Popping?

Overloaded The CircuitSome circuits can only handle a certain amount of current. The fuse will blow if you try to put more current through the circuit than it can handle.
Flammable Material In Contact With The CircuitWhen a source of flame or heat is in contact with a circuit with live wires, the circuit is overloaded, and the fuse will blow.
Damaged Electrical DevicesIf light bulbs, toasters, hair dryers, water heaters, etc., are not working properly due to damaged electrical devices, the circuit is overloaded and will trip the fuse.
Badly Bent Wires If a circuit is overloaded due to bad wiring and the wires bend from too much force, the circuit will trip a fuse if it can’t handle the current flow.
Improperly Sized FuseIf you install a fuse in a circuit with more current than the fuse can handle, the circuit will trip the fuse.
Loose WiringIf wires are loose and move around too much and don’t secure properly, they can touch each other, short out, cause a short in the circuit and trip a fuse.
Fuse KitIf you don’t install a fuse kit properly, the wires from the fuse can touch each other and cause a short. This will also cause the fuse to blow.

How Many Fuses Are in A Motorcycle, And How Do They Work?

A motorcycle has 6-10 fuses, depending on its make and year. Its fuse blocks the flow of electricity to one circuit, thus preventing the power from reaching that area. You can find fuses in a metal box near the battery.

Once you blow a fuse, you must replace it. Begin by pulling the fuse box cover off. Take the old fuse from its holder and place it on the side.

Next, take one fuse from the new pack and place it in the left holder of its slot. Be sure to put them in the same slot as before so you don’t short-circuit your electrical system by trying to fit a 10 amp when you need a 15 amp.

Push the fuse back in, being careful not to let your fingers touch the metal base of the fuse.

Place the cover back on and start your motorcycle, checking to ensure all electrical components are working properly.

If a fuse is blown again, you will likely buy the wrong replacement or have problems with your electrical system or circuits.

You should change your motorcycle’s fuses at least once a year, especially if you are rough on your bike.

Why Does My Motorcycle Keep Blowing the Ignition Fuse?

One quick note on how to use the electrical system of a motorcycle. Your motorcycle may have an Ignition Switch. This is the switch that turns on the engine when you start it.

Its most common location will be at the end of the handlebar, but it can be found under some motorcycles and even in a compartment near your seat.

Only turn the Ignition Switch on if you are starting up the motorcycle. You can also turn it off by pressing a button or turning off a screw.

The Ignition Switch is always meant to be in the ‘Off’ position. Keep it there and wait to start your motorcycle if it is on.

Where Are the Main Motorcycle Fuses Located?

In The Fuse BoxNear the steering head and Sometimes under the seat.
On The Left Side of The HeadlightIn the fuse box and On the back of the bike in a rubber cover.
On Top Of The Rear Of The TankUnder the carpet on the left side of the tank.
Underneath Seat Cover (Leather Only)Underneath plastic seat cover (textile only).
In The Passenger Foot AreaBehind the kickstand plate or fender.
Underneath The SeatBehind the rear shroud (sissy bar).
Behind The Front ShroudBy the headlight.
On The Left Side of The Fuel Tank (Behind The Shroud)Near the driver’s right foot.

 What Types of Fuses Do Motorcycles Use?

Type of FuseUses
Blade FusesUsed in motorcycle spark plugs, also known as “Miller.” and  More often, find them on older bikes.
Field FusesLess common than blade fuses,You can bury it out of sight so the bike doesn’t look ugly when the engine works.

Considered useless in today’s safety-conscious world due to lack of visibility and long-term reliability.
Zinc Chloride FusesUsed to protect electrical systems from short circuits and voltage spikes.
Often, you find it in the ignition switch connections and on the body of the bike.

In rare cases, these will be used for lighting purposes.
Ignition FusesUsed to protect against overheating of coils in spark plugs and in other electrical areas often found on motorcycle ignition units.

You can use it to protect the battery from overcharging, over-discharging, or permanent damage due to battery leakage.
Wire Gauge FusesUsed to protect against electrical shorts, also known as “fused wires.”
Metal FusesUsed to protect against electrical and magnetic noise. Also used to protect against excessive radiation (cancer and death) in radar wiring and other high-frequency signals.
Gaseous FusesUsed in the fuel injection systems of mass-produced vehicles – to protect against electrical and electrical noise. Also used in high-frequency circuits.

What Happens When the Main Fuse Blows?

When the main fuse blows, the circuit overloads, and the fuse “blows” to protect the electrical system and prevent damage or fire.

This can happen for various reasons, such as overloading an outlet with too many appliances or if there is a short circuit within the wiring in the house.

When this happens, you need to shut off all electricity to your house so that other breakages don’t occur.

It will be helpful to have all of the information on how your home’s wiring is set up before starting this process;

Call a licensed electrician for help if you aren’t sure where things are located in your home and have no one else available.

To shut off the electricity, you will need a non-contact voltage tester; you can buy these at many retail stores. Touch the tester’s probes to two bare/exposed wires and note which lights up.

Write this information for future reference, then switch off the correct circuit breaker in your main electrical box.

Note: You can also use a regular/basic DMM (digital multi-meter) for testing voltages in an existing circuit.

You will need to shut off the electricity in all the rooms with outlets, or you have installed power strips.

If there are outlets in bathrooms and kitchens, you will need these as well; turn off all of the switches to the light fixtures and lamps, as well as any outlet covers and touching any metal in these areas.

It is good to wear rubber-soled shoes during this process, as disconnecting screws for outlet covers can get very hot. Have a fire extinguisher on hand, just in case something catches fire.

How Do You Bypass A Blown Fuse?

You can try gum wrapping around the fuse and taping it back up, allowing you to make contact. If this does not work, connect the fuse back together and build the circuit again in reverse order.

Sometimes a blown fuse will cause a short internally, in which case you may need to replace or repair the fuse holder or switch.

Electrical problems usually cause blown fuses but can also occur due to bad contact. In any case, there is a definite solution.

The most common problem is that the fuse holder does not make good contact with the fuse. Many things can cause this problem.

One part of the problem may be defective connections on the fuse holder, or it may have been knocked loose while handling circuit parts or pulls during repairs.

A blown fuse will only stay blown until you remove and inspect it. The Fuse is the smallest circuit breaker in the AC power supply.

It is a thin, round plastic strip with two wires attached to it that connects one power supply circuit to another.

If the fuse has blown, then you will have no power. The other common problem is loose connections, particularly on fuses mounted inside a plastic connector case or a bulb socket.

What Size Fuses Do Motorcycles Use?

The size of fuses used in motorcycles can vary depending on the make and model of the motorcycle, as well as the electrical system it uses.

Typically, the main fuse in a motorcycle electrical system ranges from 15-30 amps. Other fuses in the electrical system may range from 5-40 amps, and some higher-powered motorcycles may use as high as 60 amps.

Why Does My Motorcycle Keep Blowing the Ignition Fuse?

It is essential to use the correct size fuse for the electrical component it protects to ensure the proper functioning and prevent damage to the component or the electrical system.

The correct size and type of fuse should be specified in the motorcycle’s owner manual, or you can obtain it from the manufacturer.

Cruiser15 Or 20 Amps.
Sport Bike20 Or 30 Amps.
Touring Bike30 Or 40 Amps
Dirt Bike10 Or 20 Amps.
Scooter5 To 10 Amps.
Dual Sport Bike20 To 30 Amps


You can use motorcycle fuse boxes for various purposes, from protecting your bike’s electronics to ensuring your engine is started safely.

It can be dangerous if you don’t understand how motorcycle fuses work or what fuses you should use.

By educating yourself on the subject and ensuring that you have the correct fuses on hand, you can ensure that your electrical system will work as well as possible and give you many years of safe riding.


Hi! I' am Tom. I faced many questions from customers about different products, and there was hardly any help on the internet. After learning all the things about these products as a manager the hard way, I decided to start a blog and help other people.

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