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4 Reasons Why Your Car Keeps Blowing the Fuel Pump Fuse

Engine Problems can present themselves in several ways. One of the most common ways to do so is for you to experience a sudden loss of power or for your car to not start entirely. There might be many reasons for this, including the fuel system, the air intake system, or even a low battery level. However, in this article, we will be focusing on fuel systems. Particularly, we will be looking into why your car keeps blowing the fuel pump fuse.

The car keeps blowing the fuel pump fuse due to several reasons. A fuse protects other components in case of surge currents. Hence, events that lead to a rise in current ultimately blow your fuse. Events such as short-circuiting, overloading the fuel pump, broken fuel pump relay, or even an old fuel pump can cause a spike in the current. A quick fix is to just replace the fuse. However, since it is likely to blow up again, it is important to investigate and remedy the root cause.

When your fuel pump fuse blows out, then the connection to the fuel pump is severed. This means that effectively the fuel pump stops working. Thus, you will have trouble starting the car back up. On the other hand, if your car is already running, then the engine might sputter and come to stop as if it suddenly ran out of fuel. At the same time, your fuel gauge will show you still have fuel left. If you have already experienced one of these, there is a high chance that your fuel pump’s fuse has been blown. Read on to find out more about why it blew and how you can fix it.

Short-circuiting or Grounding of the wires

Effects of Short circuit
Effects of short circuit | Image Credits: Pixabay

A short circuit is caused when the wire is kind of connected back onto itself. It causes a very low resistance path for the current. This is also known as grounding sometimes as the wires get directly connected to the ground terminal without any resistance in between.

Since the resistance is low, the current values are way higher leading to your car’s fuse being blown. Short-circuiting is one of the most common reasons for any fuse blowing up. This generally occurs when your wires are exposed in some way or form. While it is rare, it can happen during some electrical/mechanical maintenance or due to some debris.

There are two ways to solve this. The first method is to use the multimeter through the length of the fuel pump circuit and identify where the short circuit is. This can be rather painstaking. Alternatively, you can create your own circuit with new wires for the fuel pump. This will require some electrical knowledge and a circuit map of the car.

Since this can be a bit technically challenging, you might want to take the car to the nearest dealership.

Impurities in the fuel

Fuel Pump Source
Fuel Pump at Gas Station | Image Credits: Pixabay

If there are impurities in the fuel, the pump will have to use greater force to push the fuel to the injectors. This can be caused by a clogged fuel filter too. This high amount of torque required by the pump gives a sudden rise to the current. It will always be produced as long as the impurities aren’t removed. This is why your car keeps blowing the fuel pump fuse.

Impurities in the fuel may also lead to a reduction in performance and an increase in emissions. This could be one way to confirm the diagnosis. Another way to check is by using a multimeter and measuring the amount of current drawn by the fuel pump during operation. If the fuel pump is demanding a high value of current (compared to the manufacturer’s recommendations), then it is requiring a higher load than usual. This means that the fuel lines are probably clogged.

To fix this problem, you might want to flush the fuel tank completely and fill in fuel from a trusted source. Moreover, if the fuel filter is already clogged, then you might want to clean/replace it too! Once these steps are performed, the car should be able to start again.

To prevent this, all you need to do is fill your fuel always from a trusted gas station and ensure regular maintenance is done of your fuel filter.

Faulty fuel pump relay

Fuel Pump Relay
How a relay looks | Image Credits: Pixabay

A relay is something that controls the switching of various components in the car. If the relay is broken, there is a chance that the fuel pump does not get turned on properly when needed. Sometimes, this can lead to a spike in current as well. Because of this, your car keeps blowing the fuel pump fuse.

To identify if this is the problem, you need to take out the fuel pump relay from the fuse box and test it with the help of your car’s battery and multimeter. If the resistance between the prongs is not zero or almost zero, then there is possibly a problem with the relay.

The simple solution in this case is to replace the entire relay and you should be back on the road in no time.

Broken or old fuel pump

Fuel Pump
Fuel Pump | Image Credits: Youtube – EasyAutoFix

Finally, the last reason why your car keeps blowing the fuel pump fuse might be because your fuel pump is just old and worn out. Over time, because of impurities in the fuel, clogged fuel filters, and just normal wear and tear, the fuel pump starts losing its edge. This causes the fuel pump to exert more load than normal leading to a spike in current.

If you have ruled out all other problems in the list, then this is probably it. In such cases, you have no choice but to replace the entire fuel pump. Once done, your car should be functioning just like it used to.

Final Thoughts

It can be quite annoying when a part of your car keeps failing repeatedly. At such times, it is important to stay calm and realize that this is part of a deeper problem. Hopefully, this article gave you some insight into why your car keeps blowing the fuel pump fuse. Solving these problems often requires some basic electrical engineering know-how and a multimeter.

If you are doing the repairs at your home, remember to wear gloves to prevent any accidents. However, if you are not feeling confident, you may want to take it to the nearest mechanic. Preferably the authorized dealer since they would always have the electrical diagrams of the car at hand. With any luck, you won’t have to replace a fuel pump fuse ever again after reading this article.


Abheek is an Engineering student with a background in Automotive Engineering and Sustainable Energy Engineering. He has worked in Engine Development for a couple of years but is quite interested in Electric Vehicles too! In his free time, he likes to use his knowledge to help others with their car problems. Other times, he can be found following the sport of Formula 1.

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