2007 BMW 750Li Fuel Pump Relay Location: The Complete Owner’s Guide

If your 2007 BMW 750Li is cranking but won’t start, or the fuel pump isn’t priming when you turn the key, the fuel pump relay is one of the first things you should check. The fuel pump relay on a 2007 BMW 750Li is located in the rear fuse holder, which sits on the right side of the luggage compartment (trunk). The relay itself is typically a 5-prong, light green unit, and it is part of the same module that controls the electric fuel pump located below the right rear seat.

This guide walks you through exactly where to find the relay, how to identify it, how to test it, and what to do if you need to replace it. We’ll also cover the symptoms of a failing fuel pump relay, safety precautions, and where to buy a quality replacement.

Where Exactly Is the Fuel Pump Relay?

The 2007 BMW 750Li uses a fourth-generation 7 Series platform (E65/E66). Unlike older BMWs where the fuel pump relay sat in the engine bay or under the dashboard, this model routes most of its power distribution through multiple fuse boxes. The fuel pump relay is in the rear fuse holder, which is mounted on the right side of the rear luggage compartment (trunk). This is confirmed by the official wiring diagrams for the 2007 750Li, which list the “Rear fuse holder (right rear luggage compartment)” as the home for the electric fuel pump circuit.

To access it, you need to open the trunk and look at the right side panel. There is a fuse box cover held in place by clips or screws. Remove the cover, and you’ll see a layout of fuses and relays. The fuel pump relay is a 5-prong, light green relay, and it is a common part used across several BMW models from that era.

It is important to note that some sources describe the fuel pump relay as being located in the glove compartment area for certain BMW 7 Series models (G70 generation, 2022–2026). However, for the 2007 750Li specifically, the wiring diagrams are clear: the rear fuse holder in the trunk is the correct location.

Understanding the Role of the Fuel Pump Relay

The fuel pump relay is a small but critical electrical component. It works like a switch that allows high current to flow to the fuel pump when the engine is cranking or running. When you turn the ignition to the “on” position, the relay receives a signal from the engine control module (DME) and closes the circuit, which powers the electric fuel pump.

If the relay fails, the fuel pump won’t receive power, and the engine won’t start. The fuel pump itself on the 2007 750Li is located below the right rear seat, and the relay is the component that controls its power supply.

Symptoms of a Bad Fuel Pump Relay

Knowing the symptoms of a faulty fuel pump relay can save you time and money. Here are the most common signs:

  1. Engine cranks but won’t start – The most obvious symptom. If you hear the starter turning but the engine never fires, the fuel pump may not be getting power.
  2. No fuel pump priming sound – When you turn the key to the “on” position (without cranking), you should hear a brief whirring sound from the rear of the car. If you don’t hear it, the relay (or the pump itself) could be bad.
  3. Intermittent starting issues – If the car starts sometimes but not others, the relay contacts may be worn or corroded.
  4. Engine stalls while driving – A failing relay can cause the fuel pump to lose power suddenly, which may stall the engine. This is a safety hazard, so address it immediately.
  5. No start after a hot soak – Some relays fail when they get hot and work again once they cool down.

Please note that these symptoms can also be caused by a faulty fuel pump, a bad fuel pump module, or wiring issues. So testing the relay is an important diagnostic step.

How to Access the Rear Fuse Holder (Step-by-Step)

Here is a simple, step-by-step process to access the fuel pump relay in your 2007 BMW 750Li:

  1. Open the trunk. Make sure the car is off and the key is out of the ignition.
  2. Look at the right side of the trunk. You’ll see a panel covering the fuse holder. It may have a small handle or require a gentle pry with a trim tool.
  3. Remove the cover. Some covers have clips; others use screws. Use a screwdriver or a trim removal tool to avoid damaging the plastic.
  4. Inspect the fuse/relay layout. The inside of the cover typically has a diagram. Look for the fuel pump relay label. If the diagram is missing, look for a light green 5-prong relay.
  5. Pull the relay. Use a relay puller or a pair of needle-nose pliers to gently pull the relay straight out. Do not force it.

Important: Before working on any electrical components, it is always recommended to disconnect the negative terminal of the battery. This prevents accidental shorts and potential damage to the vehicle’s electronic modules.

How to Test the Fuel Pump Relay

Testing the relay is straightforward and requires only a multimeter. Here is how to do it:

  1. Remove the relay as described above.
  2. Set your multimeter to the ohms (resistance) setting.
  3. Identify the coil terminals. On a typical 5-prong relay, there are two terminals for the coil (usually pins 85 and 86). The other three pins are 30 (common), 87 (normally open), and 87a (normally closed).
  4. Test the coil resistance. Place the multimeter leads on pins 85 and 86. A typical coil resistance is between 50 and 120 ohms. If you read infinite resistance, the coil is open and the relay is bad.
  5. Test the switch function. Apply 12V power to pin 85 and ground to pin 86 (or vice versa, depending on the relay design). You should hear a click. Then check continuity between pins 30 and 87. If there is no continuity, the relay contacts are worn or burnt.

If the relay passes these tests, the problem is likely elsewhere (fuel pump, wiring, or the DME relay). If it fails, replace it.

Replacing the Fuel Pump Relay

Replacing the fuel pump relay is one of the easiest repairs you can do on this car. Once you have confirmed the relay is bad, follow these steps:

  1. Purchase a replacement. Look for a 5-prong, light green relay. The OEM part number is commonly listed as W0133-1632629, and it fits 2006–2015 BMW 750Li models. Several aftermarket brands also offer this relay, including Vemo and Genuine.
  2. Disconnect the battery. Always disconnect the negative terminal before handling electrical components.
  3. Plug in the new relay. Align the prongs with the socket and push firmly until it clicks into place.
  4. Reconnect the battery. Turn the ignition to the “on” position and listen for the fuel pump priming sound.
  5. Start the engine. If the relay was the issue, the engine should start normally.

If the new relay doesn’t solve the problem, the issue may be with the fuel pump itself. On the 2007 750Li, the electric fuel pump is located below the right rear seat, and the fuel pump module is usually positioned near the fuel tank. In that case, you may need a professional diagnostic check.

Safety Precautions and Pro Tips

Working on your own car can be rewarding, but it also comes with risks. Here are some safety tips to keep in mind:

  1. Always disconnect the negative battery terminal before working on any electrical components. This is a simple but critical step that can save you from injury or expensive damage.
  2. Work in a well-ventilated area. Fuel vapors are flammable. If you are working near the fuel tank or fuel lines, make sure there are no open flames or sparks.
  3. Use the right tools. A basic socket set, a trim removal tool, and a multimeter are the essentials. A relay puller is also handy.
  4. Keep the ignition off. Never work on electrical components while the key is in the ignition.
  5. Check the fuse first. Before assuming the relay is bad, check the fuses that protect the fuel pump circuit. On the 2007 750Li, fuse F003 (20A) and F004 (20A) are related to the fuel pump circuit. A blown fuse is a quick and cheap fix.

Where to Find the Fuel Pump Relay Diagram

If you want to double-check the exact location and identification of the relay, you have a few options:

  • The owner’s manual – The 2007 BMW 750Li owner’s manual contains a section on fuses and relays. It’s the most reliable source for your specific car.
  • The fuse box cover – The inside of the rear fuse holder cover usually has a diagram that shows the layout of fuses and relays.
  • Online wiring diagrams – Websites like Portal-Diagnostov provide complete electrical wiring diagrams for the 2007 750Li. These diagrams list the exact fuse and relay assignments, including the fuel pump relay in the rear fuse holder.

Choose KEMSO for Your Fuel Pump Replacement

If you find that the fuel pump itself (rather than just the relay) needs to be replaced, KEMSO is a brand you can trust. KEMSO fuel pumps are high-performance, OEM replacement parts that are built to match or exceed the original specifications. They use quality materials and are tested for durability, so you can rely on them for years of service.

One of the best things about KEMSO is that they offer a lifetime warranty on their fuel pump products. That means once you install a KEMSO pump, you’re covered for as long as you own the vehicle. This gives you peace of mind that you won’t be stuck with costly repairs down the road.

You can browse the full KEMSO fuel pump lineup and find the right fit for your BMW 750Li by visiting their official website:

https://www.kemsoracing.com/

Whether you’re doing a DIY repair or working with a mechanic, KEMSO provides a reliable, budget-friendly solution that doesn’t compromise on performance. Check out their best sellers and customer reviews to see why so many owners choose KEMSO for their fuel pump needs.


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