Many people confuse the fusible link wire with a typical fuse. But even though they perform similar duties, it’s essential to understand the specific application of each.
In today’s guide, we’ll take you through the features of a fusible link wire in detail. We’ll also elaborate on its primary applications and how to identify it in your car. Finally, we’ll give you tips on changing the fusible link if it blows.
What is a Fusible Link?
It’s a wire that selectively allows the right current amperage to pass. The fusible link wire is typically shorter and thinner than the primary wire. Primarily, it helps shield the car’s electrical circuit from power surges and short-circuiting.
If absent, a surge in electrical current flow would result in electrical faults that can damage the entire wiring system. In the worst-case scenario, it can cause a fire.
How Does a Fusible Link Work?
Repairing a Car.
- As its name suggests, it’s a typical wire with a gauge four times larger than the primary wiring system under protection. Note that a higher wire gauge means that the fusible link is thinner. It is thus capable of carrying less current than the primary wire.
- Hence, when there is a power surge, the fusible link will overheat first before the main wiring.
- Next, it will blow up and thus prevent the excess current from reaching the wiring system, shielding it. Also, the fusible link has insulation to avoid fire outbreaks when it blows up.
- This arrangement ensures you only replace the fusible link wire instead of the entire wiring.
What’s the Difference Between a Fuse and a Fusible Link?
Car Fuse.
The primary difference is in their application. You use a fuse in circuits with a current draw between an amp and 40 amps. Also, the fuse breaks the circuit immediately after its threshold rating.
But there are scenarios when a circuit experiences brief peak current surges that are not necessarily harmful. In such situations, a fuse is not applicable because of its inflexibility. The perfect alternative is the fusible link wire.
Moreover, you spend less on a fusible link than buying the typical fuse. Finally, the installation of a new one is a breeze.
Symptoms of a Bad Fusible Link
What are some telltale signs that your fusible link wire is not working as it should?
Low Battery
Car Battery.
The component is a critical part of your car’s battery charging system. Therefore, when it blows up, no power will reach the battery. So, while there are many causes of low car battery, a faulty fusible link could be one of them.
You will also experience problems operating parts that rely on the battery, such as lighting and ignition.
Warning Light Illumination
Check Engine Indicator.
If you drive a modern car, you probably know that its ‘check engine light’ lights up when something is amiss. Of course, there are other reasons it’s one, but you cannot rule out a bad fusible link.
Troubleshoot the primary problem by checking the trouble code. If you have a bad fusible link, fix it to clear the error.
Faulty Power Windows
Car electric window button.
If your power windows misbehave, the cardinal cause is probably the low battery problem. By extension, the root of such an issue can be a faulty fusible link. Therefore, as highlighted above, the first thing to check is if the fuse link is in the right shape to charge the battery.
Generally, you must always pay attention to a faulty power window problem. The component is essential to your car’s security and makes driving convenient.
Wipers not Moving
Your car’s wipers are battery-powered; thus, they will malfunction when the fuse link is not working. So, fix the problem by installing a new fuse link.
Dimmed Lights
Dim Car Headlight.
Driving with dimmed lights is quite frustrating, but solving the problem could be as simple as replacing the fuse link. Remember, a blown fuse link means less than the proper current reaches the lights.
So, to save yourself the hassle of driving in pitch darkness with dimmed lights, fix the fuse link.
The Central Locking System is not Working
You cannot open your doors and access features such as the liftgate when the central locking system is unresponsive. Since it is battery-powered, it may malfunction because of a fuse link issue.
Radio Not Functioning
There are numerous reasons why your radio is not working, and a damaged fuse link is one of them. It simply means there’s no power for it to operate. While a malfunctioning radio is not a major issue like the others discussed here, you can’t ignore it.
So, make a point of fixing the fuse link and solving this and other issues ailing your car.
How to Identify a Fusible Link?
Short circuit.
What are the criteria to identify the fusible link wire? There are several ways:
- First, check the section with a short wire. If your fusible link is the original one from the car maker, it will have a sheath covering it. So, remove the cover to access it.
- Also, there’s a considerable chance it has a different color from the other wires. Therefore, look for the short section that is colored differently.
- Thirdly, you can also identify it from its high gauge. So you can tell it from its relatively thinner profile than the other cables.
How to Test a Fusible Link?
A Digital Multimeter.
The only time to replace your auto’s fusible link is when it blows. Therefore, first, you must check if it’s in a good state to decide if replacing it is correct. Here’s the testing procedure you will follow:
- First, ensure you’ve disconnected the battery power supply to the fuse link by removing the negative terminal.
- You will need a multimeter to test if there’s continuity in the fuse link. Turn its knob to set it on the Ohm mode because you will be testing for the wire’s resistance.
- Now, place one of the prongs on the positive battery terminal. Next, to complete the circuit, place the other prong on the end of the fuse link that connects to other parts.
- Check the multimeter reading. If the fusible link is in good condition, you should have a low resistance reading.
How to Replace a Blown Fusible Link Wire
Replacing a Blown Fusible Link.
If the fuse link is in good shape, the other possible issue could be the winch wire. But if your fuse link is not working, replacing a new one is the only remedy. Here are the steps:
- Disconnect the battery terminal (the negative one) always when fixing something on the car’s electrical system. It is a prudent move to prevent the risk of electrocution.
- Next, remove the fusible link wire from the wire harness system.
- Using wire strippers, remove the covering of the new fusible link ends and connect it to the primary wire.
- We recommend soldering the connections and installing a heat shrink above the joints for additional cover.
Video Illustration:
Wrap Up
You may think of replacing a blown fusible link with a typical fuse, but it is wrong. We recommend a like-for-like replacement, such as a new fusible link. If you must install a fuse, use a slow-blow fuse.
If you install everything perfectly, your car should be up and running when you turn the ignition. Also, feel free to reach out if you have any questions.
