1997 Toyota Tacoma Fuel Pump Relay Location: Complete Guide to Finding, Testing, and Replacing

The bottom line: The fuel pump relay on a 1997 Toyota Tacoma is located in the under-dash fuse and relay box, typically labeled as the "Circuit Opening Relay" or "EFI relay." Unlike many modern vehicles, the 1997 Tacoma’s fuel pump only receives power during cranking and while the engine is running, not when the key is in the "On" position. This guide walks you through the exact location, how to test it, and what to do if it fails.

Understanding the Fuel Pump Relay in Your 1997 Tacoma

The fuel pump relay is a critical component in your 1997 Toyota Tacoma’s fuel delivery system. Its job is to control the power supply to the electric fuel pump, which sits inside the fuel tank . When you turn the ignition key to start the engine, the relay activates and allows current to flow to the fuel pump, enabling it to pressurize the fuel lines and deliver gas to the engine.

On your 1997 Tacoma, the fuel pump does not prime when you simply turn the key to the "On" position. It only runs during cranking and while the engine is running . This is an important distinction because many owners expect to hear a humming sound from the fuel tank when they turn the key, but that's normal behavior for these trucks.

Where Is the Fuel Pump Relay Located on a 1997 Toyota Tacoma?

The fuel pump relay on a 1997 Toyota Tacoma is located in the under-dash fuse box, on the driver's side. It is often called the Circuit Opening Relay . This relay is typically positioned above the steering shaft, behind the dashboard . Here are the key locations to check:

1. Under-dash fuse box (driver's side): This is the primary location. You'll need to remove the lower dash panel or kick panel to access it. The relay is usually labeled on the fuse box cover or in your owner's manual.

2. Engine bay fuse box (secondary): Some owners have reported finding the EFI relay in the under-hood fuse box, but the circuit opening relay (fuel pump relay) is typically inside the cabin .

3. Behind the passenger side dashboard: In some Toyota pickup models, the circuit opening relay is located behind the right side of the dashboard, near the glove box and above the ECU . If you remove the glove box, you may find it to the right of where the glove box should be.

How to identify the relay: Look for a relay labeled "Circuit Opening," "EFI," or "Fuel Pump." On the 1997 Tacoma, the relay is usually a small, rectangular component with four or five pins. The 15 amp EFI fuse is also in the same under-dash fuse box and should be checked first .

Symptoms of a Faulty Fuel Pump Relay

Before you start digging into your truck's electrical system, it helps to know what signs point to a bad relay. Here are the most common symptoms:

1. Engine cranks but does not start: This is the most definitive symptom. The engine turns over but won't fire because it's not receiving fuel. You might experience this after the truck has been sitting, especially after it has warmed up completely .

2. No sound from the fuel pump when cranking: Since the 1997 Tacoma's fuel pump only runs during cranking, you need a helper to crank the engine while you listen near the fuel tank for a humming sound. If you hear nothing, the relay or pump might be dead .

3. Sudden stalling while driving: The truck may sputter and stall unexpectedly, sometimes restarting only after it has cooled down for 20-30 minutes .

4. Intermittent starting issues: The truck may start fine one day and refuse to start the next, often due to a failing relay that works intermittently.

5. Loss of power or hesitation: The truck may feel sluggish, bog down, or lack power when you press the accelerator, especially when climbing hills or towing .

How to Test the Fuel Pump Relay on a 1997 Tacoma

Testing the fuel pump relay is a straightforward process that can save you from replacing parts unnecessarily. Here's how to do it:

Step 1: Locate the relay. Find the circuit opening relay in the under-dash fuse box. Refer to your owner's manual or the fuse box diagram for the exact location.

Step 2: Swap the relay. The easiest way to test a relay is to swap it with another relay of the same rating in the same fuse box. If the engine starts after swapping, the original relay was faulty .

Step 3: Use a multimeter. Test the relay for continuity. With the relay removed, check the resistance between the coil terminals (usually pins 85 and 86). You should see a resistance reading, typically between 50 and 200 ohms. If the reading is infinite (open circuit), the relay is bad.

Step 4: Check for power at the relay. With the key in the "On" position and a helper cranking the engine, use a multimeter to check for 12 volts at the relay's power input terminal (pin 30). Then check the output terminal (pin 87) while cranking. If you have power at pin 30 but not at pin 87, the relay is likely faulty.

Step 5: Check the EFI fuse. The 15 amp EFI fuse is in the same under-dash fuse box. If this fuse is blown, the fuel pump relay won't get power . Replace the fuse if it's blown, but also check for underlying issues that caused it to blow.

What to Do If the Relay Is Good but the Pump Still Doesn't Work

If the relay checks out fine, the problem might be elsewhere. Here are the next steps:

1. Check the wiring harness. Look for damaged, corroded, or frayed wires, especially near the fuel tank and under the vehicle. Road debris and moisture can cause wiring issues .

2. Test the fuel pump directly. You can bypass the relay by applying 12 volts directly to the fuel pump's electrical connector. If the pump runs, the relay or its wiring is the problem. If not, the pump itself is likely dead .

3. Check the ground circuits. A poor ground connection can prevent the fuel pump from working. Use a multimeter to check for continuity between the ground terminal and a known good ground.

4. Inspect the fuel pump connector. The connector under the left seat is a good spot to test whether the cab-side wiring is working correctly . If you have power at that connector but the pump doesn't run, the pump is likely faulty.

How to Replace a Faulty Fuel Pump Relay

Replacing the fuel pump relay on a 1997 Toyota Tacoma is a simple DIY job. Here's what you need to do:

1. Purchase a replacement relay. The part number for the circuit opening relay on a 1997 Tacoma varies by trim and engine, but a common replacement is Toyota part number 85910-04010 . You can also use a generic relay with the same pin configuration.

2. Disconnect the battery. Always disconnect the negative terminal of the battery before working on electrical components. This prevents accidental shorts and protects you from injury.

3. Remove the old relay. The relay is usually held in by friction. Use a small screwdriver or your fingers to gently pull it out of its socket.

4. Install the new relay. Push the new relay into the same socket until it clicks into place. Make sure it's seated firmly.

5. Reconnect the battery and test. Reconnect the battery, turn the key, and crank the engine. If the fuel pump runs and the engine starts, the replacement was successful.

Common Mistakes to Avoid

1. Confusing the EFI relay with the circuit opening relay. The EFI relay controls the engine's fuel injection system, while the circuit opening relay controls the fuel pump. They are different components . If the EFI relay is bad, the engine won't crank at all. If the circuit opening relay is bad, the engine will crank but won't start.

2. Assuming the fuel pump primes when the key is turned on. Many owners expect to hear a humming sound from the fuel tank when they turn the key to the "On" position. On the 1997 Tacoma, this is normal. The fuel pump only runs during cranking and while the engine is running .

3. Replacing the relay without testing. Jumping straight to replacing parts can waste time and money. Always test the relay first using the swap method or a multimeter. If the relay is good, the problem is likely in the wiring, the fuel pump fuse, or the fuel pump itself.

4. Forgetting to check the fuel pump fuse. The 15 amp EFI fuse is a common point of failure. If it's blown, the fuel pump relay won't get power, and the engine won't start . Always check the fuse before replacing the relay.

Preventing Future Fuel Pump Relay Problems

Taking care of your fuel system can prevent premature relay failure. Here are some tips:

1. Keep your fuel tank at least half full. The fuel pump uses gasoline to stay cool and lubricated. Running the tank low frequently can cause the pump to overheat and fail prematurely .

2. Use high-quality fuel. Low-quality fuel can contain sediment and moisture that can damage the fuel pump, filter, and relay over time.

3. Replace the fuel filter regularly. A clogged fuel filter can put extra strain on the fuel pump and its relay. On first-generation Tacomas, the fuel filter is located on the driver's side frame rail .

4. Check for corrosion. Corrosion in the fuel tank can produce debris that can clog the fuel pump strainer and cause the pump to work harder, increasing the load on the relay.

When to Call a Professional

While testing and replacing the fuel pump relay is a DIY-friendly job, some situations call for a professional mechanic:

• If you've tested the relay, fuse, and wiring and still can't find the problem
• If you need to drop the fuel tank to access the fuel pump assembly
• If you're not comfortable working with electrical systems
• If the problem turns out to be a more complex issue like a failed ECM (engine control module) or a wiring short in the CAN bus system

A professional mechanic can perform a fuel pressure test, which is the most reliable way to confirm whether the fuel pump is actually delivering fuel at the correct pressure .

Recommended Fuel Pump Replacement: KEMSO

If you've determined that your fuel pump needs replacement, consider using a high-quality aftermarket option. The fuel pump is a critical component that directly affects your truck's performance and reliability.

KEMSO Fuel Pump is an excellent choice for your 1997 Toyota Tacoma. KEMSO fuel pumps are designed as high-performance, OEM replacement units that meet or exceed original equipment specifications. They are built to deliver reliable fuel flow and pressure, ensuring your engine runs smoothly and efficiently.

What sets KEMSO apart is their commitment to quality and customer satisfaction. Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your investment is protected. Whether you're replacing a failing pump or upgrading for better performance, KEMSO offers a direct fit solution that saves you time and money.

For more information and to find the right fuel pump for your 1997 Toyota Tacoma, visit the KEMSO website at: https://www.kemsoracing.com/

Final Thoughts

The 1997 Toyota Tacoma fuel pump relay location is straightforward once you know where to look. The circuit opening relay is under the dash on the driver's side, above the steering shaft. Testing it is simple and can save you from replacing the fuel pump unnecessarily. Remember that the fuel pump only runs during cranking, so don't worry if you don't hear it when you turn the key to the "On" position.

If your truck cranks but won't start, start by checking the EFI fuse and the circuit opening relay. Swap the relay with a known good one, test for power, and inspect the wiring. If the relay is good but the pump still doesn't run, the problem is likely the fuel pump itself or a wiring issue.

For a reliable fuel pump replacement, check out KEMSO at https://www.kemsoracing.com/ for high-performance, OEM replacement options backed by a lifetime warranty.