Purchasing a car is a tremendous investment, so when your fuel mileage becomes an issue, you need to take it seriously. While there could be a lot of causes a few causes for this, a failing fuel pump relay is one of them.

Most times, you might not even notice that you have a bad fuel pump relay some bigger issues  like your car engine not starting; therefore, it’s  recommended to test it once in a while. You can spend money to have someone else test your fuel pump relay, or you can test it by yourself.

Testing the relay of a fuel pump is relatively easy, as it does not have many parts. The most common component to burn out or break include the contact and the coil. When either of these starts to failing, the current to the electrical circuit will be also fail. This means your fuel pump will stop to function properly.

Take note of the following steps and know how to troubleshoot your fuel pump by yourself.

1 – Find the Fuel Pump Relay

First,ensure that you have enough light and room to work. Then, open your vehicle’s hood and locate the fuse panel. The majority of cars made today have the fuel pump relay located near here, and the fuel pump relay should look like a small plastic box that has four to five electrical terminals.

However, some fuel pump relays arrive in different shapes and sizes, so it’s best to find your manufacturer’s diagram if you’re having trouble locating your fuel pump relay. You may have to look at the engine compartment more thoroughly, or you may find it under the dashboard. The fuse box should be clearly marked on the back or inside of itself.

2 – Take out the Fuel Pump Relay

Unplug the fuel pump relay, but don’t  break the cover and connecting tabs. Place it on a work surface.

3 – Know the Components

Basically, there are four pins (terminals) on the fuel pump relay. One is for input voltage, one is the ground pin, one is the load pin that goes to the fuel pump, and one heads to the battery. To figure out which pin is which, there will usually be numbers written on the bottom of the relay that shows the pin positions, or you can find a wiring diagram from your relay’s specific manufacturer.

4 – Set the Multi-meter or Ohmmeter up

Whether you are using an ohmmeter or multi-meter, you’ll have to set it to resistance mode.

Connect your multi-meter or ohmmeter probes to the relay. One probe should connect to the pin that heads to the fuel pump, and the other should connect to the pin that heads to the battery.

5 – Test the Fuel Pump Relay

You should use either a 12V battery or voltage regulator to test the relay. Connect your ground connection on the power supply to the ground pin on the relay.

Touch the power supply’s trigger to the input pin. The relay will close, and you should have continuity between the two pins that the meter is linked to.

You should also notice a clicking noise coming from the fuel pump relay. This noise is the solenoid inside the relay pulling it shut to connect the two posts together.

If your meter does not indicate continuity from the fuel pump pin and the battery pin, or if you do not hear a clicking from the fuel pump relay, you need to change your fuel pump relay