how to direct wire a fuel pump

How to Direct Wire a Fuel Pump? Pump Wiring Easy Steps!!!

Running the fuel pump directly to the battery is an easy and quick way to improve the vehicle’s performance and fuel economy. By doing this, you can send more volts of power directly to your fuel pump. And you can increase the pressure for a stable and consistent flow of fuel to your vehicle’s fuel tank. If you are planning to direct wire your fuel pump, make sure you know what you are getting yourself into. And also have a thorough knowledge of how to ‘fuel pump relay bypass .’ Because if the fuel pump is not correctly wired, your pump will fail to carry the fuel to the carburetor of your vehicle. So, in this article, we are going to walk you through how to direct-wire a fuel pump, the troubleshooting necessity, and the tips for staying safe during the wiring process etc., so you can work on it like a pro.

What is a Fuel Pump? 

The fuel pump is what you call a pump placed inside the fuel tank of your vehicle. This pump is used to carry fuel from the tank to the vehicle’s engine.

This fuel is carried by creating the necessary pressure, as needed, to move the fuel from one point to another.

The fuel pump will be in constant motion when we drive the vehicle, so when the car is running low on gas or fuel, the motion will slow down, indicating the drain in your fuel tank.

Sometimes the movement observed will be slow when there is an overheating, contamination, or wear and tear of components.

Why Would you Need to Direct Wire a Fuel Pump? 

The simplest answer we can give why you would need to direct wire a fuel pump is mainly to improve your vehicle’s performance and fuel economy by increasing the flow rate and the fuel pressure of your engine.

Direct wiring a fuel pump is where we use a relay and fuse to bypass and directly connect the fuel pump to the battery. Here are some of the situations where we direct wire the fuel pump. 

  1. We tend to direct wire the fuel pump when the factory wiring that we use is not sufficient.
  2. Direct wiring your fuel pump improves the performance of your vehicle by preventing fire bursts.
  3. You can also prevent a drop in the voltage of the power supply in your vehicle and other problems with the factory wiring.

It can be a big risk when you re-direct wiring, especially if it is your first time. So, make sure you have the necessary knowledge and expertise. Otherwise, you will end up facing a messy risk of fire hazards and electrical short circuits. This will damage your fuel pump due to incorrect wiring. It is better to be safe than sorry when direct wiring. Make sure to get the needed help from professionals to direct wire.

How to Direct Wire a Fuel Pump? 

To direct wire a fuel pump, you need to first make sure you have the following sorted correctly. Let us cruise you through the initial requirements;

  1. When direct wiring your car, make sure the battery voltage must be compatible with the fuel pump of the car.
  2. Next, be sure to secure all the required connections in a correct manner and use a heavy gauge wire so that the pump can receive adequate power. 

The followings are steps and instructions to direct wire the fuel pump

  1. The first step of direct wiring your fuel pump is to locate the fuel pump. In case you are wondering, it is located inside your fuel tank. And for diesel engines, there are two pumps, one at the engine and the other inside the tank.
  2. The next step is to find the wiring for the connection. We use two wires for this connection. One is to control power, and the other is for the ground. 
  3. Next, we usually have to install a relay to bypass. We will be using a fuse in between to wire the relay connecting the fuel pump and the battery. 
  4. Now, in this step, we will Connect the power wire coming from the fuel pump to the relay. And then, we connect the vehicle chassis to the ground wire.
  5. Now it is time to test the wire and see whether the fuel pump is getting enough power.
  6. Finally, secure the wire with zip ties/ electrical tape to avoid loose connections.

One thing to remember when direct wiring a fuel pump is that it varies from vehicle to vehicle and model to model. So, make sure to check the owner’s manual and get professional help when doing direct wiring. Also, remember to follow the safety tips and protocols to reduce the risk of fire hazards.

How Does It Troubleshoot Fuel Pump Wiring Issues? 

Here are some tips on how to troubleshoot fuel pump wiring issues. In many cases, we observe that it’s either a problem with a blown-up fuel fuse or a bad case fuel pump relay. Sometimes it can also be a defect in the ground path or damaged wiring.

  1. First, check the pump fuse, and the trouble can be due to a blowout. If that is the case, replace the pump fuse.
  2. Next, use a multimeter and check for the fuel pump relay for continuous connection and make sure to replace it immediately if you happen to find a faulty relay. 
  3. Another troubleshooting tip is to check for the wiring by inspecting the wiring process for any damages, loose connections, and corrosion. If you happen to find any such issues, fix them immediately.
  4. You can use a multimeter to test the voltage of the fuel pump. The voltage of the battery should match the voltage of the pump.
  5.  Sometimes loose connections, corrosion, or damages can be observed in the ground wire. You better replace such damaged and corroded wires with better new ones.
  6. Test the fuel pump because sometimes the issue lies in the main component itself. We do this by applying a direct voltage to the pump. It may indicate if the pump is faulty.

How Does It Troubleshoot Fuel Pump Wiring Issues

Always get help from an expert to troubleshoot. This way, one can direct wire the fuel pump without any issues. No need to worry about risky fire hazards with expert assistance.

Tips for Staying Safe During the Direct Wiring Process

We will provide you with some safety tips to direct wire the fuel pump. So you can avoid injury to yourself and protect your vehicle at the same time. Remember that direct wiring a fuel pump is quite dangerous as a process to handle. This can happen when we do not connect properly. 

  1. You better disconnect the battery before direct wiring your fuel pump. This safety tip will help you prevent an electrical shortage.
  2. Wear safety and protection gear like safety eyewear, gloves, and head cover to avoid burns and electric shocks.
  3. To help you prevent or avoid incorrect wiring on the fuel pump, you can get a wiring plan and diagram. This can save you time and trouble.
  4. Wiring the fuel pump requires a lot of tools and components like a wire cutter, strippers, multimeters, gauge wires etc., so you don’t miss any steps to correct wiring.
  5.  Use electrical tape or zip ties to tighten any loose connections; otherwise, you will be in trouble for loose connections and electrical circuit shortages.

It is always better to get help from an expert or professional in the field in case you fear and doubt your ability to carry out the process on your own. It will save you a lot of trouble. 


Directly running the fuel pump to the battery is a method many people opt for as it is inexpensive and easy. But unfortunately, it is only a short-term fix and not well recommended for the long run.

This short-term fix has many benefits, like it increases the pressure of fuel being delivered to the engine, helps avoid flickering of lights, creates a more consistent flow of fuel to the engine, and prevents corrosion of the battery terminals.

You can use a heavy gauge, relay and fuse wire for direct wiring. And do not forget that not all vehicles work well with direct wiring of the fuel pump.

Watch this one,

Video Credits – Ratty Muscle Car

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