Fuel Pump Not Getting Power

Fuel Pump Not Getting Power? [Causes + Solutions]

You’re ready to hit the road, but your car won’t start. One of the most frustrating culprits behind this scenario is a fuel pump that’s not receiving power. When the fuel pump doesn’t get power, you are bound to face tons of other issues as well.

In this comprehensive guide, we discuss common causes and symptoms of fuel pump not getting power. Let’s start.

What are the Common Causes of a Fuel Pump Not Getting Power?

The common causes of a fuel pump not receiving power include issues with the fuel pump relay, a faulty fuel pump fuse, or problems with the wiring harness. We’ll explain these more.

Faulty Fuel Pump Relay

The fuel pump relay is a crucial component that controls the electrical circuit supplying power to the fuel pump. We have seen that when this important component fails it interrupts the flow of electricity to the fuel pump.

The fuel pump relay failures occur due to internal electrical faults.

Blown Fuel Pump Fuse

Most vehicle components are protected by a fuse, and it’s the same with a fuel pump. The fuel pump fuse is designed to blow if there’s a short circuit or overload in the system.

If the fuel pump fuse blows, electricity won’t reach the fuel pump, resulting in a lack of power in the fuel pump. This could happen due to various reasons such as a malfunctioning fuel pump or a short circuit in the wiring.

Issues with the Wiring Harness

The wiring harness carries electrical signals throughout the vehicle, including to the fuel pump. If there are problems with the wiring harness it can disrupt the flow of electricity to the fuel pump.

This can prevent the fuel pump from receiving the needed power to function properly.

Fuel Pump Control Module Malfunction

Some vehicles are equipped with a fuel pump control module that regulates the operation of the fuel pump. If this module malfunctions it can interfere with the power supply to the fuel pump.

Corroded Electrical Connections

Over time, electrical connections in the fuel pump circuit can become corroded resulting in poor conductivity. This corrosion can hamper the flow of electricity to the fuel pump.

What Gives Power to the Fuel Pump?

The power to the fuel pump is provided by the vehicle’s electrical system, specifically through the fuel pump relay and fuse.

Here, the fuel pump relay acts as a switch, controlling the flow of electricity from the battery to the fuel pump. When you turn the ignition key, the fuel pump relay receives a signal from the engine control unit (ECU) to activate, allowing power to flow to the fuel pump.

Additionally, as we explained, the fuel pump circuit is protected by a fuse, which prevents electrical overload and damage to the system. Together, the fuel pump relay and fuse ensure that the fuel pump receives the necessary power to deliver fuel from the gas tank to the engine.

If either the relay or fuse malfunctions, it can disrupt the power supply to the fuel pump, leading to starting or performance issues. 

What are the Symptoms of a Fuel Pump Not Receiving Power?

When a fuel pump is not receiving power, you will notice one or a few of the below-mentioned symptoms.

Engine Cranks But Doesn’t Start

One of the most common signs of a fuel pump not receiving power is when you turn the ignition key, and the engine cranks but fails to start. When the fuel pump fails to supply fuel to the engine, it will impact the combustion process.

No Fuel Pressure

Using a fuel pressure gauge, you can verify if the fuel pump is delivering adequate pressure to the fuel injectors. If there is no pressure or insufficient pressure, it indicates a problem with the fuel pump not receiving power. 

Engine Stalling or Hesitation

A fuel pump not receiving power consistently can cause intermittent stalling while driving. This occurs because the fuel pump intermittently loses power. As a result, the engine may sputter and stall during acceleration.

Vehicle Won’t Start After Sitting

If your vehicle fails to start after sitting for an extended period, it could be a sign of a fuel pump not getting power. When the vehicle sits idle for a long time, there is a possibility of the fuel pump losing power due to electrical issues.

Check Engine Light Illuminates

In some cases, if the pump doesn’t get power, it can trigger the check engine light on the dashboard. This occurs because the ECU detects a problem with the fuel system.

Vehicle Runs Roughly or Lacks Power

If the fuel pump loses power while driving, it can cause the engine to run roughly. This happens because the engine is not receiving a proper supply of fuel, leading to poor combustion.

What to do If the Fuel Pump Doesn’t Get Power?

If your fuel pump isn’t receiving power, start by checking the fuel pump relay and fuse for any signs of damage or malfunction.

Test the power supply to the fuel pump using a multimeter to ensure the voltage is reaching the pump.

Then, inspect the wiring harness for any damaged or corroded wires, and repair or replace them as needed.

In addition, check the functionality of the fuel pump control module and ignition switch.

If you’re unable to diagnose the issue yourself, we recommend seeking assistance from a professional mechanic.

You May Also Like

How to Prime Mechanical Fuel Pump? Step-by-Step Guide


Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *