1989 Honda Civic Fuel Pump Relay Location: The Complete Guide to Finding, Testing, and Replacing It

If your 1989 Honda Civic cranks but won't start, the fuel pump relay is the first thing you should check. On the 1989 Honda Civic, the fuel pump relay – also called the PGM-FI main relay – is located under the driver's side dashboard, above the hood release lever, near the left kick panel and fuse box. It is a small, rectangular black box with a reddish-brown bottom, secured by a single 10mm bolt. Knowing exactly where to find it and how to test it can save you hours of frustration and hundreds of dollars in unnecessary repairs.

What Is the Fuel Pump Relay and Why Does It Matter?

The fuel pump relay is a small electrical switch that controls power delivery to the fuel pump inside your gas tank. When you turn the ignition key to the ON position, the relay engages for about two to three seconds to prime the fuel system, then stays engaged while the engine runs . If this relay fails, your fuel pump won't receive power, and your engine won't start or will stall unexpectedly.

On the 1989 Honda Civic, the fuel pump relay is actually part of a larger component called the PGM-FI main relay. This unit contains two separate relays in one housing: one controls the fuel injectors, and the other controls the fuel pump . This is why many mechanics refer to it simply as the "main relay" rather than just the fuel pump relay.

Symptoms of a Bad Fuel Pump Relay on a 1989 Honda Civic

Knowing the warning signs can save you from being stranded. Here are the most common symptoms:

1. Engine cranks but won't start. This is the most definitive sign. You turn the key, the starter motor works fine, but the engine never fires up because no fuel reaches the combustion chambers .

2. No fuel pump prime sound. When you turn the key to the ON position (without starting), you should hear a brief buzzing or whining sound from the rear of the car near the fuel tank. If you don't hear this sound, the relay may not be sending power to the pump .

3. Intermittent stalling. The engine runs fine for a while, then suddenly dies without warning. After a few minutes, it might restart. This pattern strongly suggests a failing relay that works intermittently due to heat or vibration .

4. Heat sensitivity. The problem is often worse in hot weather. The car will run fine in the mornings and evenings when it's cool, but in the hot afternoons the check engine light may come on and the car will not start . This is a classic sign of a failing main relay on 1988-1991 Civics and CRXs .

5. Clicking sounds from under the dash. You may hear clicking sounds from the driver's side kick panel area, but the car won't start consistently .

Exact Location of the Fuel Pump Relay on a 1989 Honda Civic

The fuel pump relay on a 1989 Honda Civic is located in the same spot on all models from 1988 to 1991 sold in the United States . Here is exactly where to find it:

Step 1: Sit in the driver's seat and look under the dashboard on the left side, near where your left knee would hit the side wall.

Step 2: The relay is mounted above the hood release lever, tucked up behind the lower dash panel near the fuse box . It is bolted to the upper inside portion of the door hinge pillar on the driver's side .

Step 3: The relay has a black case with a reddish-brown bottom. It typically has a white connector with 7 pins arranged in a 2x4 pattern (with one pin missing). On the outer case, you should see the code "RZ-0063" in white lettering .

Step 4: To access it, you may need to remove the lower dash cover or the under-dash fuse box cover. Some owners find it easier to remove the small coin pocket or storage compartment on the left side of the dash .

Step 5: The relay is secured with a single 10mm hex bolt. You may need a swivel socket to reach it .

The Honda part number for this main relay is 39400-SH3-003 . It fits the 1987-1992 Honda Civic, CRX, and other models with the 1.5i and 1.6i engines .

How to Test the Fuel Pump Relay

Before replacing the relay, you can test it to confirm it's the problem. Here are several methods:

The Tap Test (Quick Check): With the key in the ON position, tap the relay area gently with a screwdriver or your hand. If the fuel pump suddenly primes or the car starts, the relay is likely failing internally . This is a temporary fix but confirms the diagnosis.

Listen for the Click: Turn the key to the ON position and listen for a click from the relay area near the driver's left knee. If you hear the click but the fuel pump doesn't run, the internal contacts may be burned .

The Heat Test: If the car won't start when hot, open the doors, let the cabin cool down, and try again. If it starts after cooling, the relay is heat-sensitive and needs replacement .

Bench Test with a Multimeter: Remove the relay and test it with a 12V power source and a multimeter. The relay has 7 pins labeled 1 through 7 (or 1 through 8 with one empty). Here is the testing procedure:

• Connect battery positive to pin 2 and negative to pin 1. Check for continuity between pin 5 and pin 4. If there is no continuity, the relay is bad .

• Connect battery positive to pin 5 and negative to pin 3. Check for continuity between pin 7 and pin 6. If there is no continuity, the relay is bad .

• Connect battery positive to pin 6 and negative to pin 1. Check for continuity between pin 5 and pin 4. If there is continuity after all three steps, the relay is good .

Visual Inspection: On older relays, look for cracked or dull solder joints. These are common failure points and can sometimes be temporarily fixed by reflowing the solder joints, but replacement is more reliable .

Common Misdiagnosis and What to Check First

Many people replace the fuel pump, the ECU, or other components when the real problem is the main relay. Before you start replacing parts, do these simple checks:

Check the fuses first. The 1989 Honda Civic has a 15A fuse for the PGM-FI main relay in the engine compartment fuse box (fuse No. 7) . The passenger compartment fuse box also has a 10A fuse (No. 2) that powers the starter solenoid and PGM-FI main relay . Check both with a test light or multimeter.

Listen for the fuel pump. Turn the key to the ON position. You should hear a soft hum from the rear of the car for about two seconds. Silence suggests the pump isn't being commanded, which often points to the relay .

Watch the check engine light. At key-on, the check engine light should illuminate, then go out after a couple of seconds. If it never lights, the ECU may not be powered (relay issue) .

Check for spark. If you have spark but no fuel, the problem is likely fuel-related. If you have no spark and no fuel, the main relay is a strong suspect because it powers both the fuel pump and the ECU, which controls the spark .

How to Replace the Fuel Pump Relay on a 1989 Honda Civic

Replacing the main relay on a 1989 Civic is a straightforward job that most DIYers can do in about 30 minutes.

What you need: A new PGM-FI main relay (Honda part number 39400-SH3-003), a 10mm socket or wrench, and possibly a swivel extension for the socket.

Step 1: Disconnect the negative battery cable to prevent any electrical shorts.

Step 2: Remove the lower dash cover on the driver's side. This may involve removing a few screws or clips.

Step 3: Locate the relay above the hood release lever, tucked up near the left kick panel. It is a black rectangular box with a reddish-brown bottom.

Step 4: Remove the 10mm bolt that secures the relay to the bracket. You may need a swivel socket to reach it .

Step 5: Unplug the wiring connector from the relay. The connector is a white 7-pin plug.

Step 6: Install the new relay in the reverse order. Plug in the connector, secure the bolt, and reinstall the dash cover.

Step 7: Reconnect the battery and test the car. Turn the key to the ON position and listen for the fuel pump to prime. Then start the engine.

Cost of Replacement

A new main relay from a Honda dealer typically costs around $58 to $70 . Aftermarket versions are available for less. If you take it to a shop, the total cost including labor can range from $104 to $225 depending on your location and the shop rates .

Why You Should Consider a High-Quality Replacement Fuel Pump

While the main relay is often the culprit when your 1989 Honda Civic won't start, sometimes the fuel pump itself has failed. If you've replaced the relay and still have issues, or if your fuel pump is simply worn out after decades of service, upgrading to a reliable replacement is essential.

For a dependable fuel pump replacement, consider KEMSO brand fuel pumps. KEMSO offers high-performance fuel pumps that are designed as OEM replacements, meaning they meet or exceed the original equipment specifications for your vehicle. Each KEMSO fuel pump is built for durability and reliable performance, and it comes with a lifetime warranty for your peace of mind. Whether you're restoring a classic 1989 Civic or keeping your daily driver on the road, a KEMSO fuel pump ensures you get the fuel delivery your engine needs.

To browse KEMSO fuel pumps and find the right fit for your Honda Civic, visit their website at: https://www.kemsoracing.com/

Final Thoughts

The fuel pump relay on a 1989 Honda Civic is a common failure point, but it's also one of the easiest problems to diagnose and fix. If your car cranks but won't start, start by checking the fuses, then listen for the fuel pump, and finally locate and test the main relay under the driver's dash. The part is affordable and the replacement takes less than an hour. If the relay tests good but the fuel pump still doesn't run, the pump itself may need replacement. In that case, a quality replacement like a KEMSO fuel pump will keep your Civic running reliably for years to come.

For more information on fuel pumps and replacement parts, visit KEMSO Racing at https://www.kemsoracing.com/