2007 GSXR 750 Fuel Pump Relay Location: Complete Guide to Finding and Testing It

If your 2007 Suzuki GSX-R 750 cranks but won't start, the fuel pump relay is one of the first things to check. The fuel pump relay on a 2007 GSXR 750 is located under the passenger seat, mounted to the subframe on the right side of the bike, near the ECU. This small black relay controls power delivery to the fuel pump, and when it fails, your bike gets no fuel pressure and won't fire up. Understanding its location, how to test it, and what to do if it's bad can save you hours of frustration and expensive diagnostic fees.

Where Exactly Is the Fuel Pump Relay on a 2007 GSXR 750?

The fuel pump relay is tucked away under the passenger seat. Here's how to get to it:

  1. Remove the passenger seat by pulling the release latch or using the key to unlock it.
  2. Look on the right side of the subframe, close to the rear shock absorber mount.
  3. You'll see a small, rectangular black relay with a 4-pin connector. It's often mounted on a rubber bracket.
  4. The relay is typically the same part used for the fan relay, so the two relays on that bracket are physically identical. This is a common swap method for quick testing.

On the 2007 GSXR 750, the fuel pump relay is part number 38740-26E00 or 38740-26E01, and it's a direct plug-and-play unit . The same relay is used on many Suzuki models, including TL1000, Bandit, and GSX models from the same era.

How the Fuel Pump Relay Works

The fuel pump relay is an electromagnetic switch. When you turn the key to the ON position, the ECU (Engine Control Unit) sends a ground signal to the relay coil, which closes the internal contacts and sends battery voltage to the fuel pump. The pump runs for about 2–3 seconds to prime the fuel system, then stops until the engine starts or the bike is cranked. If the relay fails, the pump never gets power, and you get a no-start condition.

On the 2007 GSXR 750, the ECU controls the fuel pump relay ground circuit. If the ECU detects a fault with the ignition system or the tip-over sensor, it will not ground the relay, and the pump stays off . This is a key safety feature, but it also means a C42 fault code (ignition signal issue) can cause the same symptoms as a bad relay.

Symptoms of a Bad Fuel Pump Relay

A failing fuel pump relay on a 2007 GSXR 750 usually shows these signs:

  • Engine cranks but won't start. This is the most common symptom. The starter turns over fine, but the engine never fires because there's no fuel pressure.
  • No fuel pump prime sound. When you turn the key to ON, you should hear a faint whirring or buzzing from the fuel tank area for about 2 seconds. If you don't hear it, the relay or pump isn't getting power.
  • Intermittent starting issues. Sometimes the bike starts fine, other times it cranks but won't fire. This points to a relay with worn contacts that work only when they feel like it.
  • The bike dies while riding. If the relay fails completely while you're on the road, the engine will shut off suddenly and won't restart.

How to Test the Fuel Pump Relay

Testing the relay is straightforward and requires only a multimeter. Follow these steps:

Step 1: Locate and remove the relay. Unplug the 4-pin connector from the relay. You can pull the relay out of its rubber mount for easier access.

Step 2: Check for power at the relay socket. With the key ON, use a multimeter set to DC voltage. Probe the Red/Blue wire in the connector. You should see battery voltage (around 12V). This is the main power supply to the relay . If you don't have power here, check the main fuse and the ignition switch circuit.

Step 3: Check the ground signal from the ECU. On the 2007 GSXR 750, the Yellow/Red wire is the ECU-controlled ground for the relay coil. With the key ON, this wire should show 0V (ground) for about 2 seconds, then go to 12V (open circuit) after the prime cycle. If you never see a ground signal, the ECU is not triggering the relay, which could mean a bad ECU, a fault code, or a tip-over sensor issue.

Step 4: Test the relay itself. Remove the relay and apply 12V to the coil terminals (pins 85 and 86 on a standard relay, but check your specific pinout). You should hear a distinct click. With power applied, use your multimeter to check continuity between the switched terminals (pins 30 and 87). If you don't get continuity, the relay is bad and needs replacement.

Common Fixes for Fuel Pump Relay Problems

Swap with the Fan Relay

The fan relay on the 2007 GSXR 750 is identical to the fuel pump relay. Simply swap them. If the bike starts and runs after the swap, your fuel pump relay was bad. This is a zero-cost diagnostic that works every time .

Check for Fault Codes

Put the bike into dealer mode by shorting the two pins in the diagnostic connector (usually under the passenger seat or near the battery). Turn the key ON and read the code on the dashboard. A C42 code means the ECU is not seeing a proper ignition signal, which prevents the ECU from grounding the fuel pump relay. This is a common issue on 2007–2009 GSXR 750 models, especially if the ignition switch or resistor has been tampered with . A C29 code points to the secondary throttle valve actuator (STVA) or its TPS sensor, which can also affect starting.

Inspect the Ignition Switch

Many 2007 GSXR 750 owners with starting issues find that the problem isn't the relay at all, but the ignition switch. The ignition switch contains a resistor that the ECU reads to verify the correct key. If this resistor is broken or corroded, the ECU won't enable the fuel pump relay . You can test the ignition switch by checking resistance between the Red and Orange wires at the switch connector. You should see a specific resistance value, typically around 100 ohms on these bikes.

Check the Ground Connections

A poor ground at the battery negative terminal, the frame ground, or the ECU ground can cause the fuel pump relay to act erratically. Clean all ground connections with a wire brush and apply dielectric grease. On the 2007 GSXR 750, the main ground wires are Black/White and Black/Brown, and they connect to the frame near the battery and the ECU .

Why the Fuel Pump Relay Fails

The fuel pump relay is an electromechanical part, and over time the internal contacts wear out from arcing. The relay is also subject to vibration, heat, and moisture under the seat. On a 2007 GSXR 750 that's 19 years old, the relay is well past its expected service life. If you haven't replaced it, consider it a maintenance item.

Preventative Maintenance Tips

  • Replace the relay every 5 years as a proactive measure. It's a cheap part that can leave you stranded.
  • Keep the relay connector clean. Apply dielectric grease to prevent corrosion.
  • Don't use the starter for extended periods. Long cranking sessions can overheat the relay coil.
  • Check the fuel pump itself. Even with a good relay, a failing pump motor (drawing too many amps) can damage the relay contacts over time. A healthy fuel pump on the 2007 GSXR 750 draws about 4.5 amps at 40 psi .

When to Replace the Fuel Pump Instead of Just the Relay

If you've tested the relay, swapped it with the fan relay, and confirmed the relay is good, but the bike still won't start, the problem is likely the fuel pump itself. The 2007 GSXR 750 uses an in-tank fuel pump assembly. If the pump motor is seized, the wiring inside the tank is corroded, or the fuel filter is clogged, replacing the relay won't help. You'll need to pull the fuel pump assembly from the tank and inspect or replace the pump.

Recommended Upgrade: KEMSO Fuel Pump for Your 2007 GSXR 750

If you need to replace the fuel pump itself, don't settle for a cheap, low-quality unit. The KEMSO fuel pump is the ideal OEM replacement for the 2007 GSXR 750 and delivers superior performance and reliability compared to stock. KEMSO pumps are designed as direct drop-in replacements, meaning they fit perfectly into your existing fuel pump housing without any modifications.

Why choose KEMSO?

  • High Performance: KEMSO fuel pumps deliver up to 200 liters per hour at 43 psi, which is significantly more flow than the stock pump's 60–80 LPH. This means better fuel delivery under load and improved throttle response.
  • OEM Replacement: Every KEMSO pump is built to match or exceed original equipment specifications. The pump body is made from corrosion-resistant alloy steel, and the kit includes gradient density fuel strainers, Viton o-rings, and wiring connectors to cover all model variations.
  • Lifetime Warranty: KEMSO stands behind every pump with a lifetime warranty. You buy it once, and it's covered for as long as you own your bike. No other aftermarket pump offers this level of confidence.
  • Compatible with Ethanol Fuels: KEMSO pumps are designed to handle modern ethanol-blended gasoline without degrading, which is a common issue with older stock pumps.
  • Tested for Quality: Each pump is individually tested before leaving the factory, ensuring consistent flow and pressure performance.

Installing a KEMSO fuel pump is a straightforward job that you can do yourself with basic hand tools. The kit includes everything you need for a complete replacement: the pump, fuel strainers, o-rings, tank seal, and wiring connectors.

Visit KEMSO's official website to find the exact fuel pump for your 2007 GSXR 750 and take advantage of their lifetime warranty: https://www.kemsoracing.com/

Final Thoughts

The fuel pump relay on your 2007 GSXR 750 is a small component that plays a huge role in getting your bike started and running. It's located under the passenger seat on the right side of the subframe, and it's easy to test with a multimeter or by swapping it with the fan relay. If the relay checks out but you still have no fuel pressure, the problem is likely the pump itself, the ignition switch resistor, or a fault code stored in the ECU.

Don't let a simple relay failure ruin your riding season. Knowing where it is and how to test it gives you the power to diagnose and fix the issue yourself in minutes. And if you're looking at a full fuel pump replacement, choose a quality upgrade from KEMSO – it's a one-time purchase backed by a lifetime warranty that will keep your GSXR 750 running strong for years to come.

For more information and to browse the full lineup of KEMSO fuel pumps, visit: https://www.kemsoracing.com/


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