Car fuses do not have a guaranteed lifespan. This means that they can get melted at any time. Almost all car owners experience a blown 50 amp fuse if they drive the same car for a long period of time. This happens when the main component malfunctions and requests a current higher than it can withstand. So, in order for the main component not to get burnt, the 50 amp fuse acts as a shield and gets blown instead. But what does a blown 50 amp fuse look like?
In this blog post, I am going to talk about what 50 amp fuses are used in cars, what does a blown 50 amp fuse look like, and how to replace a blown 50 amp fuse.
What Is 50 Amp Fuse Used For In Cars
A 50 amp fuse is used in cars for feeding several circuits including an engine idling with no lights on which typically draws 50 amps, or it can be used as the main fuse which feeds more than one circuit and is usually labeled as B+(battery positive). Basically, any component of the vehicle that requires 50 amps to run properly will be fed from a 50 amp fuse.
Fuses have been used for many years, starting all the way back from 1967. Modern vehicles have well over 50 fuses that are used to protect cables, wires, and electrical components. The way a fuse protects electrical components in a vehicle is it acts as a shield. When an electrical component starts to malfunction, it can draw more power from the car battery than it can handle. This is where fuses come into play.
For example, if an electrical component that is protected by a 50 amp fuse draws more than that voltage, the current will go from the battery and into the fuse. If the current is higher, it will cause the 50 amp fuse to melt and act as an open circuit. This means that the high current will stop at the 50 amp fuse and will not continue to the main component and burn it.
There are several 50 amp fuses in vehicles. Typically, when a car idles with no accessories on, it draws 50 amps of power. Also, on some vehicles, the 50 amp fuse can be labeled as B+ which means that it will act as the main fuse that feeds more than one electrical circuit.
A single 50 amp fuse can be responsible for feeding electrical power to more than one component.
What Does a Blown 50 Amp Fuse Look Like
A 50 amp fuse has a fuse wire that runs from one copper conductor to another copper conductor. The fuse wire acts as a bridge between the copper conductors and allows for proper current to flow through the 50 amp fuse and into the main component. However, a blown 50 amp will have a melted fuse wire from a sudden overload of electrical current and will look very differently from a brand new fuse.
You can tell that a 50 amp fuse is blown if you visually inspect it. The fuse wire that is supposed to allow current to flow through it will appear like melted/broken.
When the 50 amp fuse is blown, no electrical current will pass through it. This means that the main component that the 50 amp fuse was used to feed it has requested a larger voltage than it can handle. So, when the current went from the battery and into the 50 amp fuse, it automatically blew the fuse wire. The 50 amp fuse was designed that way and it actually acts as a fail-safe switch and melts before the high current reaches the main component.
If you suspect that one of the 50 amp fuses is blown, you can visually inspect it. Since the 50 amp fuse has a cartridge casing, it can be a bit difficult to check it. So, you will need to remove the top lid of the 50 amp fuse and visually inspect it. A properly working 50 amp fuse will have a fuse wire (metal alloy strip) that runs from one copper conductor to another copper conductor. If the 50 amp fuse is blown, the fuse wire will be melted/broken. At this point, you will need to replace the blown 50 amp fuse.
How To Replace a Blown 50 Amp Fuse
Fuses are designed to melt in order to protect the main component from being burnt. This means that they are destined to fail often. But do not worry. Replacing a blown 50 amp fuse is not as hard as people think. I will guide you through the process. So, without any further delay, here is how to replace a blown 50 amp fuse.
1. Order a new 50 amp fuse
When replacing a blown 50 amp fuse, it is important that you have a brand new 50 amp fuse on hand. Please do not use any old fuses because it is simply not worth it. A new 50 amp cartridge-style fuse costs around $1.30 but can save you a lot of money in the long term.
So, you can either order a new 50 amp fuse on amazon.com or go to your local part store. Whatever you decide to do, just make sure that you get the exact same fuse as your old one. A 50 amp fuse can be both in blade-style or cartridge-style.
2. Open the hood and locate the fuse box
Locating the fuse box can be difficult if you are a young DIY mechanic. Pull the latch underneath your steering wheel to open the hood. Then, as you stand in front of the engine, concentrate on the right side of the engine bay. You will notice a box that most of the time will be labeled as a fuse and relay box. That is what we are looking for.
3. Open the fuse box and locate the blown 50 amp fuse
The fuse box is usually secured by either a tab or a bolt. So, press on the tab or remove the bolt and open the fuse box. Underneath the fuse box lid, you will see a diagram of what each fuse is used for. Locate the blown 50 amp fuse with the help of the diagram.
Usually, there are two or three cartridge-style 50 amp fuses and a couple of blade-style 50 amp fuses. Take your time locating the blown 50 amp fuse.
4. Remove the blown 50 amp fuse
Once you locate the blown 50 amp fuse, it is time to remove it. First, try to remove the fuse with your hands. However, if the fuse is stuck, you can use pliers. When removing a blown 50 amp fuse, make sure that you don’t wiggle it around because you can damage the ports. It is important that you just pull it upwards in a straight line.
A note of caution. Some fuses just blew and do not do any damage to the container. However, a 50 amp fuse can sometimes melt, depending on how much current went through it. So, if the 50 amp fuse is melted, disconnect the battery and proceed with caution. Use gloves and pliers to remove the melted parts.
5. Visually inspect the blown 50 amp fuse
Just to be sure if you pulled out the correct blown 50 amp fuse, you will need to visually inspect it and then test it with a multimeter. Because the 50 amp fuse is in a cartridge, you will need to remove the lid. To do so, you will need to press the clips on each side with a toothpick or a needle and pull the lid off.
Once the lid is removed, you can visually inspect the 50 amp fuse. If the 50 amp fuse is blown, you will notice it right away. There is a metal alloy strip running from one side of the fuse to the other. It kind of looks like a bridge. If the ”bridge” is disconnected in the middle, it means that the 50 amp fuse is blown. However, sometimes is not this simple to diagnose a blown fuse because the fuse wire can break on a hard-to-see spot. This is why I always check it with a multimeter.
6. Test the blown 50 amp fuse with a multimeter
As I said before, some fuse wires can break in a hard-to-see place. This is why it is important to test the fuse with a multimeter. Get a multimeter and set it on ohms. Before you perform the test, touch both ends of the multimeter and remember the reading. Then, get the 50 amp fuse and insert the red and black wires from the multimeter into the fuse ports located on the backside.
If you get the same reading as you did when you only touched the wires from the multimeter, it means that the fuse is working correctly. However, if you get a different reading, it means that the fuse is blown. So, if you touch the wires and you get 1 ohm, and then you test the fuse and you get 0 ohms, it means that the fuse is blown.
7. Install the new 50 amp fuse
Before you install the new 50 amp fuse, make sure that the fuse port is clean. If there is any debris left there, it can cause the fuse to blow out immediately. Then, simply insert the new 50 amp fuse all the way down. Close the fuse box by pressing it until you hear a click. That’s it.
How Much Is a 50 Amp Fuse
A blade-style 50 amp fuse costs around $3 and a cartridge-style fuse costs around $1.30 on amazon.com. However, you can go to your local part store and probably get it for the same price, but without paying for shipping.