Fuel Pump Relay TESTING and REPLACEMENT

So the first step is locating where the fuel pump relay lives. In this case, it lives on the kicker panel on the driver's side of the vehicle. So in other words, right here is around where your foot would be located, and right here is the piece of, usually a plastic piece you just remove, and you see this bracket. So we have two 10-millimeter bolts. We're going to remove both bolts, peel this back, and remove the fuel pump relay so we can go ahead and test and see if it's working correctly. Here's our fuel pump relay. As you can see, it has a really funky looking harness connector. Now to remove this, right where my index finger is, this harness connection just moves up. It's a tight connection, which is exactly what you want being a fuel pump relay. But this just moves up a little bit, and then you can remove the connector from the fuel pump relay assembly. Now if you're curious on how do I find this, the specific fuel pump relay on my vehicle, use Google Images. That's the number one thing I always recommend. So if you have, let's say, a Nissan Maxima, you would type in, let's say you have a 2000 Maxima, you would type in 2000 Nissan Maxima fuel pump relay. A lot of times you can dig up images showing exactly where the fuel pump relay is located, and that's the quickest thing I always recommend. Just use Google Images. It's a huge time saver. So let me remove the connector. We'll apply power to the harness on the bench, and I'll show you on how you can quickly test to see if the relay is working or not. Just want to move this up with your index finger, and then pull back. And that's it. Here's your harness, your fuel pump relay. So we have everything on the bench, and let me quickly go over what we're looking at here. Of course, here's our fuel pump relay. This is a digital multimeter. If you plan on doing your own auto repair, grab one of these. $15 or $20. You can do a ton of testing, really throughout the whole car, using a multimeter. So grab one of these. This is an external battery source, and I'll explain why we need this. And just alligator clips, two of them, black and red in this case. So what we want to do is recreate what happens in your vehicle every time you turn the key. What happens is every time you turn the key, inside your car, of course, you have a car battery, which is 12 volts. Now that 12 volts is sent to the relay. Inside the relay, you have circuitry that makes a connection and sends the 12 volts then over to the fuel pump. That's all that this does. That's why they're inexpensive. It's a very simple device. Now, what we want to do is recreate that since now the relay's out of the vehicle. And to do that, I need a 12-volt power source. So I'm using, in this case, an RC LiPo battery pack. You can use anything you have lying around that has 12 volts worth of power. If you want to use your car battery, you can do that. Just be super careful. If ever you disconnect the negative terminal to the battery, just be really, really careful. Don't cross the wires. So if we take a look at the relay, this is actually quite simple to read. If you're curious on what these symbols mean, what this means is when 1 and 2, if you take a look at this symbol here between 1 and 2, all that this means is when 1 and 2 is energized with 12 volts worth of power, 3 and 5 then makes a connection. So right now, 3 and 5 is not connected. That's why we don't have a straight line. That's why there's a break in the line. But once 1 and 2 is energized, 3 and 5 makes a connection. So that's what we need to test. Because if 1 and 2 is energized and 3 and 5 is not making a connection, then the relay is bad. So to test this, we're going to provide 12 volts of power to numbers 1 and 2, and then verify that 3 and 5 are making a connection. Now if we turn this over, right here, we see number 1 and number 2. So we're going to hook up number 1 and 2 to the battery pack and take a reading with the multimeter with number 3 and number 5. Now once we hook up 1 and 2, we should hear this click. And that's just a very good sign that this is working correctly. But really use the multimeter because I have seen these relays still click with the battery source, but they're still bad. So just follow the steps if you're a little confused. So the first step is grab your multimeter and you want to use the symbol that looks like a wireless network. In other words, whenever you're on your smartphone or laptop or desktop, if you're looking for a wireless access point, you see this symbol and that's what we want. So just turn it to that and we just have to find the right mode and right here. So that's the symbol you want to see on the multimeter. So what we're going to do, I'm going to take black to black, and be careful when you do this, right to red. All right. And then it doesn't matter which one you do. So we're going to power number 1, number 2. And you hear it click. You hear that? So that means it's making a connection which is what you want. And then you take the multimeter and we should hear an audible sound like this. Okay. So just touch number 3, number 5, and there you go. And it's just a bad connection. That's why it's not really continuous. But there you go. So that verifies that this relay is working correctly. If you're not seeing these same results, then the relay is bad and it needs to be replaced.