Where Is The Fuel Pump Relay? Symptoms & How to Test

Jerry Wilson
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What is a Fuel Pump Relay and What Does it Do?

A fuel pump relay is a part you would find in the relay box located near the fuse box under the hood of your car. When the fuse box gets a signal from the ignition switch telling it to start the engine, it sends that information to the relay box. The relay closes an electrical circuit which in turn sends a signal to the fuel pump, which allows fuel to flow through the car.

If the fuel pump relay is faulty, it may prevent your car from starting. So it is important to be able to identify and test fuel pump relay problems. When a relay is not operating properly, there will be an obvious tell tale indication of the problem.

Forcing the car to start without the relay will result in the engine turning over, but the fuel not pumping. If this happens, the problem is obviously the relay. Although these are common symptoms of a bad relay, it is still best to have the car diagnosed by a professional to make sure that is the problem.

Where is the Fuel Pump Relay Located?

The fuel pump relay is located in the engine compartment of the car. It’s connected to the fuel pump.

You can find the fuel pump relay between the firewall (the metal frame between the engine compartment and the passenger cabin) and the engine compartment.

You’ll see the fuel pump relay behind the firewall when you open the engine compartment. The relay is mounted to the wall next to the firewall.

Symptoms of a Bad/Failing Fuel Pump Relay

Often, if your fuel pump relay is failing, you won’t see any noticeable pieces failing or have any visible problems. You may start to notice symptoms like:

The fuel pump is not getting power.

The car is not starting.

The alternator is not charging.

The dash lights in the car are dim.

The engine runs worse than usual.

The engine stalls frequently.

The most common symptoms of a failing or bad fuel pump relay are those listed above.

How to Check and Replace a Bad Fuel Pump Relay

The main function of the fuel pump relay is to sense when the engine is turned off and turn on the fuel pump. The relay is a small box with a number of electrical relays, wires, and terminals. Typically, the Fuel Pump Relay will be wired to the battery, the ignition switch (car with key) and the fuel pump.

When you turn the key to the “On” position, an electrical circuit will close and power will flow through the relay to power the fuel pump. Without a working fuel pump relay, the fuel pump is completely unable to function.


Asking “where is the fuel pump relay?” is like asking for directions to your destination. You may need to drive a little out of your way, but you will be sure to find your destination. In the same way, the relay may be a little difficult to find, but once you do, you will see that it is really not that complicated to fix.

This is a good problem to have, but it is a problem nevertheless. You just need to follow the instructions and you will have it figured out in no time.

If you have to replace the relay, be sure to use parts supplied by a reputable manufacturer. If you try to save a few bucks and use a relay that’s not specifically designed for your car, you will just end up paying even more money and time to fix issues in the future.

Just because this is easy to find, doesn’t mean it’s easy to fix. If you need more help, make sure to contact a professional to repair your fuel pump relay correctly.