1998 Subaru Forester Fuel Pump Relay Location: The Complete Guide to Finding, Testing, and Replacing It

The bottom line: The fuel pump relay on a 1998 Subaru Forester is located in the main fuse box under the hood, on the passenger side, near the firewall. It is a small, square relay typically labeled "Fuel Pump" or "Fuel Pump Relay" on the fuse box cover diagram. If your Forester cranks but won't start, the fuel pump relay is one of the first things you should check.

Why the Fuel Pump Relay Matters

Your 1998 Subaru Forester relies on an electric fuel pump to deliver gasoline from the tank to the engine. The fuel pump itself is a workhorse, but it doesn't run on its own. It needs electricity, and that electricity flows through the fuel pump relay. This relay acts as a switch. When you turn the ignition key to the "On" position, the engine control unit sends a signal to the relay, which then closes the circuit and sends power to the fuel pump. The pump runs for a few seconds to prime the fuel system, then shuts off until the engine starts. If the relay fails, the pump never gets power, and your Forester won't start.

The fuel pump relay is a common failure point on older Subaru models, including the 1998 Forester. After 25-plus years of service, the relay's internal contacts can wear out, corrode, or simply stop making good electrical contact. The good news is that replacing the relay is one of the cheapest and easiest repairs you can do. It costs about $10 to $20 for a new relay, and it takes roughly five minutes to swap it out. Before you start replacing expensive parts like the fuel pump itself, it is smart to check the relay first.

Locating the Fuel Pump Relay on a 1998 Subaru Forester

The fuel pump relay on the 1998 Subaru Forester is located inside the main fuse box, which is mounted under the hood. Here is how to find it step by step:

1. Open the hood. Park your Forester on a level surface and make sure the engine is off and cool. Pull the hood release lever inside the cabin, then lift the hood and secure it with the prop rod.

2. Find the main fuse box. The fuse box is a black plastic rectangular box located on the passenger side of the engine bay, near the firewall. It is usually tucked close to the strut tower. You can't miss it — it is about the size of a paperback book and has a removable lid.

3. Remove the fuse box cover. The cover has clips on the sides. Press them in and lift the cover straight up. On the underside of the cover, you will see a diagram that shows the location and function of each fuse and relay. Look for the label that says "Fuel Pump" or "Fuel Pump Relay." On the 1998 Forester, the fuel pump relay is typically a small, square, dark-colored relay, often with five pins. It is usually located near the center of the fuse box, but the exact position can vary slightly depending on the trim level.

4. Identify the relay. The fuel pump relay looks different from the fuses. Fuses are small, flat, and usually clear or colored plastic rectangles. Relays are larger, boxy, and solid. On the 1998 Forester, the fuel pump relay is often a standard 12-volt, 30-amp relay. If you are unsure, compare it to the diagram on the cover. The diagram will show a small square or rectangle with the label "Fuel Pump."

5. Check for a second relay location. Some 1998 Forester models also have a fuel pump relay located in the interior fuse box, which is under the dashboard on the driver's side. However, the primary and most commonly accessed relay is the one under the hood. If you do not find it in the main fuse box, check the interior fuse box on the driver's side kick panel.

How to Test the Fuel Pump Relay

Before you buy a new relay, you can test the old one to see if it is actually bad. Here is a simple way to do it using a multimeter or even just by listening.

Method 1: The Listening Test

This is the easiest test. It requires no tools and works most of the time.

1. Open the fuse box under the hood and locate the fuel pump relay.
2. Have a helper sit in the driver's seat and turn the ignition key to the "On" position (do not start the engine).
3. Listen carefully near the relay. You should hear a distinct click sound as the relay engages. This click means the relay's internal electromagnet is working and the switch is closing. If you hear no click, the relay is likely dead or not receiving a signal.
4. You can also listen for the fuel pump itself. The fuel pump is located inside the fuel tank, which is under the rear seat. Have your helper turn the key to "On" again while you listen near the rear passenger door. You should hear a quiet whirring or humming sound for about two seconds as the pump primes the system. If you hear the pump running but the car still won't start, the relay is probably fine, and the problem might be elsewhere (like a clogged fuel filter or a dead pump). If you hear nothing from the pump, the relay or the pump circuit is the likely culprit.

Method 2: The Multimeter Test

If you have a digital multimeter, you can test the relay more precisely.

1. Remove the fuel pump relay from the fuse box.
2. Set your multimeter to measure resistance (ohms).
3. Look at the relay's pins. Standard relays have four or five pins numbered 30, 85, 86, 87, and sometimes 87a. Pins 85 and 86 are the coil terminals. Pins 30 and 87 are the switch terminals.
4. Touch the multimeter probes to pins 85 and 86. You should get a reading between 50 and 120 ohms. If the reading is infinite (open circuit), the coil is burned out and the relay is bad.
5. Next, test the switch. Touch the probes to pins 30 and 87. You should see infinite resistance (open circuit) because the switch is normally open. Now, apply 12 volts to pins 85 and 86 using a small battery or a power supply. You should hear a click, and the resistance between pins 30 and 87 should drop to nearly zero (closed circuit). If it does not, the relay's internal contacts are worn out.

Common Symptoms of a Bad Fuel Pump Relay

Knowing the symptoms can save you a lot of time. If you notice any of these signs, the fuel pump relay is a good place to start your diagnosis.

1. Engine cranks but won't start. This is the most obvious symptom. The starter motor turns the engine over, but the engine never fires up. The fuel pump is not getting power, so no fuel reaches the injectors.

2. No sound from the fuel pump. When you turn the key to "On," you should hear the fuel pump prime for a couple of seconds. If you hear nothing, the pump is not getting power, and the relay is a likely cause.

3. Engine starts then stalls. If the relay is intermittent, the engine might start but then die after a few seconds. This happens because the relay loses contact after the initial prime.

4. The fuel pump relay is hot. If the relay is working but has bad internal contacts, it can get hot to the touch. This is a sign of high resistance, which can cause the relay to fail completely.

5. The check engine light comes on. On the 1998 Forester, a failing fuel pump relay can trigger a diagnostic trouble code, often related to the fuel pump circuit. Common codes include P0230 (Fuel Pump Primary Circuit Malfunction) or P0231 (Fuel Pump Secondary Circuit Low).

How to Replace the Fuel Pump Relay

Replacing the fuel pump relay is straightforward. You do not need any special tools, just a steady hand and a few minutes.

1. Buy the correct relay. Take the old relay to an auto parts store or look up the part number online. The 1998 Subaru Forester uses a standard 12-volt, 30-amp relay. You can also buy a universal relay that fits. Make sure the pin layout matches.

2. Disconnect the negative battery terminal. This is a safety precaution. It prevents accidental shorts and keeps the electrical system safe.

3. Remove the old relay. Locate the fuel pump relay in the fuse box under the hood. Grip the relay firmly and pull it straight up. It may be tight, but it will come out. Do not twist or wiggle it too much, as the pins can bend.

4. Install the new relay. Align the pins of the new relay with the socket in the fuse box. Press it straight down until it is fully seated. You should feel it click into place.

5. Reconnect the battery. Reattach the negative battery cable.

6. Test the new relay. Turn the ignition key to "On" and listen for the click and the fuel pump priming sound. If you hear the pump, the relay is working. Start the engine and let it idle for a few minutes to make sure everything is running smoothly.

Other Causes of a No-Start Condition

If you replace the fuel pump relay and the car still won't start, the problem could be elsewhere. Here are other common causes for a 1998 Subaru Forester.

1. A bad fuel pump. The fuel pump itself can fail after years of use. It is located inside the fuel tank and is not serviceable without removing the tank or accessing it through the rear seat. A failing fuel pump often makes a whining noise before it dies completely. If the pump is dead, you will hear no sound from the tank when you turn the key.

2. A clogged fuel filter. The fuel filter is mounted under the hood, near the passenger side strut tower. On the 1998 Forester, the fuel filter is a metal canister with two fuel lines connected to it. Over time, the filter can become clogged with debris, especially if the fuel tank is contaminated. A clogged filter restricts fuel flow, causing the engine to sputter, lose power, or fail to start. Subaru recommends replacing the fuel filter every 30,000 miles on the 1998 Forester .

3. A blown fuse. The fuel pump circuit also has a fuse, usually located in the same fuse box under the hood. Check the fuse labeled "Fuel Pump" or "Fuel Pump Circuit." If the fuse is blown, the pump will not get power even if the relay is good. Replace the fuse with one of the same amperage.

4. A faulty ignition switch or wiring. Over time, the ignition switch can wear out, or the wiring to the fuel pump relay can become corroded or damaged. This is less common than relay failure, but it is worth checking if you have ruled out the relay, fuse, pump, and filter.

5. A bad engine control unit (ECU). This is rare, but the ECU controls the signal to the fuel pump relay. If the ECU is faulty, it may not send the ground signal to the relay, preventing the pump from running. This is usually a last-resort diagnosis.

Preventative Maintenance Tips

To keep your 1998 Subaru Forester running reliably, follow these simple tips.

1. Keep your fuel tank at least a quarter full. Running the tank low on fuel is one of the leading causes of premature fuel pump failure. The fuel in the tank acts as a coolant and lubricant for the pump. When the tank is low, the pump runs hotter and can overheat, which shortens its lifespan .

2. Use quality fuel from reputable stations. Low-quality fuel contains more contaminants and water, which can clog the fuel filter and damage the fuel pump . Stick to name-brand gas stations.

3. Replace the fuel filter every 30,000 miles. On the 1998 Forester, the fuel filter is a serviceable part. Replacing it at the recommended interval prevents debris from reaching the fuel pump and the injectors .

4. Address symptoms early. If you notice the engine hesitating, stalling, or making a whining noise from the rear of the car, have the fuel system checked immediately. Catching a problem early can prevent you from being stranded and avoid damage to other fuel system components .

5. Check the fuel pump relay periodically. The relay is a wear item. If you are doing other maintenance on your Forester, it is a good idea to pull the relay and inspect it for corrosion or damage. The cost of a new relay is minimal, and replacing it proactively can save you a headache later.

Recommended Upgrade: KEMSO Fuel Pump for Your Subaru

If you do need to replace the fuel pump on your 1998 Subaru Forester, or if you simply want to upgrade to a more reliable unit, the KEMSO brand is an excellent choice. KEMSO specializes in high-performance fuel pump assemblies that are designed as direct OEM replacements for a wide range of vehicles, including Subaru models.

Why choose KEMSO for your Subaru Forester fuel pump?

High-performance engineering. KEMSO fuel pumps are designed for optimal fuel delivery. They ensure your engine gets the precise amount of fuel it needs for smooth operation and maximum efficiency. Whether you are daily driving your Forester or taking it off-road, a KEMSO pump delivers consistent performance.

OEM replacement quality. These pumps are manufactured to match factory specifications exactly. Installation is straightforward, and you can trust the fit and function. The pump comes with the necessary strainer and gasket, so you do not have to reuse old components that could lead to leaks or poor performance.

Lifetime warranty. KEMSO stands behind their products with a lifetime warranty. This gives you peace of mind that your investment is protected for as long as you own your vehicle. If the pump ever fails, you are covered.

Competitive pricing. KEMSO offers premium quality at a more affordable price compared to dealership parts. You save money without sacrificing reliability. For a 1998 Subaru Forester, the KEMSO fuel pump is a direct replacement that fits perfectly and works reliably.

You can browse their full selection of fuel pumps for Subaru and other vehicles at their website. The site provides detailed product information, compatibility guides, and customer support to help you find the exact pump for your car.

Visit KEMSO Racing today: https://www.kemsoracing.com/

Final Thoughts

The 1998 Subaru Forester is a rugged and reliable vehicle, but like any older car, it has its weak points. The fuel pump relay is one of those parts that can fail without warning, leaving you stranded. Knowing where to find it and how to test it is a simple skill that can save you time and money. The relay is located in the fuse box under the hood, on the passenger side near the firewall. Testing it takes just a few minutes with a multimeter or even just your ears. If the relay is bad, replacing it costs about $10 and takes five minutes.

If you have replaced the relay and the car still won't start, check the fuel pump fuse, the fuel filter, and the fuel pump itself. The fuel pump on the 1998 Forester is a robust unit, but it can fail after 25 years of service. When it is time to replace the pump, choose a quality replacement like KEMSO to ensure long-term reliability.

Regular maintenance is the key to keeping your Forester on the road. Keep the fuel tank at least a quarter full, use quality fuel, replace the fuel filter on schedule, and address any symptoms of fuel system trouble early. With proper care, your 1998 Subaru Forester will continue to serve you for many more years.

For more information on fuel pump options and to find the right replacement for your Subaru Forester, visit https://www.kemsoracing.com/.