1991 Volvo 740 Fuel Pump Relay Location: The Complete Guide to Finding, Testing, and Replacing It
If your 1991 Volvo 740 cranks but won’t start, or if it stalls unexpectedly while driving, the fuel pump relay is the first thing you should check. On a 1991 Volvo 740, the fuel pump relay is located behind the ashtray in the center console, inside the main fuse and relay panel. It is a white rectangular relay, about 1 inch by 3 inches by 2 inches, positioned toward the driver’s side of the panel . This single component is responsible for sending power to both the fuel pump and the fuel injection system, and when it fails, it can mimic the symptoms of a bad fuel pump . Replacing it costs around $25 and takes about 15 minutes, making it the cheapest and fastest diagnostic step you can take.
Where Exactly Is the Fuel Pump Relay on a 1991 Volvo 740?
The fuel pump relay sits inside the fuse and relay panel that is mounted behind the center console ashtray. This is the same panel that contains most of the car’s fuses and several other relays . To access it, you need to remove the ashtray and the surrounding trim.
Here is the step-by-step process to reach the relay:
Step 1: Remove the ashtray. Pull the ashtray out of the center console. It should slide out without tools.
Step 2: Remove the trim around the cigarette lighter. Once the ashtray is out, you will see a plastic trim piece surrounding the cigarette lighter socket. Gently pry this trim off. It may be held in place by clips.
Step 3: Remove the two screws. Behind the trim, you will find two screws—one at the top and one at the bottom. Remove these screws using a Phillips head screwdriver .
Step 4: Pull out the storage tray. With the screws removed, the entire storage tray assembly (which includes the cigarette lighter) will come out. This exposes the fuse and relay panel.
Step 5: Locate the white relay. Look toward the driver’s side of the panel. The fuel pump relay is white and rectangular, measuring approximately 1 inch by 3 inches by 2 inches . It has six pins and is rated at 15 amps .
On most 1991 Volvo 740 models, this relay sits in position "E" in the relay panel. If you are facing the panel from the driver’s seat, position "E" is in the middle row, on the left side .
What Does the Fuel Pump Relay Look Like?
The fuel pump relay on a 1991 Volvo 740 is easy to identify once you know what to look for. It is a white plastic block with six metal prongs on the bottom. The part number is typically 3523608 or 1347603 . The relay measures about 45 mm tall, 42 mm long, and 27 mm wide .
The key visual cues are:
- Color: White. This is the most distinctive feature. Most other relays in the panel are black, blue, or green.
- Shape: Rectangular, not square.
- Size: It is larger than most of the smaller cube-shaped relays in the panel.
If you see a white relay in the fuse panel behind the ashtray, that is almost certainly your fuel pump relay.
Why Does the Fuel Pump Relay Fail?
The fuel pump relay on a 1991 Volvo 740 is a common failure point for several reasons. Understanding why it fails can help you prevent future problems.
Heat and age. The relay is located behind the center console, which is not a well-ventilated area. Over time, the internal solder joints can develop cracks due to repeated heating and cooling cycles . These cracks eventually cause intermittent or complete loss of electrical contact.
Constant current load. The fuel pump relay carries a significant electrical load whenever the engine is running. This constant current flow gradually wears out the internal contacts and the electromagnetic coil inside the relay.
Vibration. The 740’s engine and road vibrations can accelerate the wear on the relay’s internal components, especially if the relay is not firmly seated in its socket.
Symptoms of a Bad Fuel Pump Relay
A failing fuel pump relay can cause a range of symptoms. Recognizing these symptoms early can save you time and money.
Engine cranks but won’t start. This is the most common symptom. When you turn the key to the start position, the engine turns over but never fires up. You may not hear the fuel pump prime for 1–2 seconds when you first turn the key to the "on" position .
Intermittent stalling. The engine may run fine for a while, then suddenly shut off without warning. After waiting 30 seconds or so, the engine may restart and run fine again . This is a classic sign of a failing relay with cracked solder joints that lose contact when they heat up.
No fuel pump noise. If you listen carefully near the rear of the car when you turn the key to the "on" position, you should hear a faint hum from the fuel tank for about 1–2 seconds. If you hear nothing, the fuel pump relay is a prime suspect .
Car starts but dies shortly after. The engine may start, run for a few seconds, and then stall. This happens because the relay provides power to the fuel pump during startup, but the internal contacts fail to stay closed once the engine is running.
How to Test the Fuel Pump Relay
Before you buy a new relay, you can test the existing one. This takes only a few minutes and requires no special tools.
Method 1: The swap test. This is the easiest method. Locate the fuel pump relay in the panel behind the ashtray. Find another relay of the same size and shape. On many 1991 Volvo 740s, the fog light relay (position "F" in the relay panel) is a compatible swap . Simply pull out the fuel pump relay and plug in the fog light relay. If the car starts and runs normally, the fuel pump relay is bad.
Method 2: The listening test. Turn the ignition key to the "on" position (do not start the engine). Listen for a click from the relay panel behind the ashtray. You should also hear a 1–2 second hum from the fuel tank area. If you hear the click but no hum, the relay is working but the fuel pump or wiring may be faulty. If you hear no click at all, the relay is likely bad.
Method 3: The jumper wire test. This test is for experienced DIYers. Remove the fuel pump relay. Use a short piece of wire to jump the appropriate terminals in the relay socket. The correct terminals to jump are typically terminals 30 and 87. Consult a wiring diagram for your specific vehicle. If the fuel pump runs when you jump these terminals, the relay is bad. Be careful with this test—jumping the wrong terminals can cause a short circuit.
What Happens If You Replace the Fuel Pump Relay and It Still Doesn’t Start?
If you replace the fuel pump relay and your 1991 Volvo 740 still won’t start, the problem lies elsewhere. Here are the next steps to check.
Check the fuel pump fuse. The fuel pump fuse is located in the same fuse panel behind the ashtray. On a 1991 Volvo 740, fuse number 1 (25 amps) protects the fuel pump circuit . Pull the fuse and inspect it. If the metal strip inside is broken, replace the fuse.
Check the fuel pump itself. The in-tank fuel pump is located under the carpet on the left side of the trunk, near the axle. There is an access panel on the floor of the trunk . Remove the carpet, pull back the panel, and check the electrical connector. Corrosion at this connector is a common problem on older Volvos .
Check the crankshaft position sensor (CPS). The CPS is located on top of the transmission bellhousing, between the cylinder head and the firewall. If this sensor fails, the engine will not receive a signal to fire the fuel pump or the ignition system. A bad CPS can cause the same symptoms as a bad fuel pump relay .
Check the radio suppression relay. On some 1991 Volvo 740 models, there is a black relay located near the power steering reservoir in the engine bay. This is called the radio suppression relay, and it provides power to the fuel injectors. If this relay fails, the engine will crank but not start .
Are There Different Fuel Pump Relay Locations for Different 1991 Volvo 740 Models?
Most 1991 Volvo 740 models use the same relay location, but there are a few exceptions.
Standard LH-Jetronic system. If your 1991 Volvo 740 is equipped with the Bosch LH-Jetronic fuel injection system (which is the most common system), the fuel pump relay is behind the ashtray, as described above. This system uses a single large relay module that contains two relays inside—one for the ECU and fuel injection, and one for the fuel pump .
Regina (Rex-Regina) system. Some 1991 Volvo 740 models were equipped with the Regina fuel injection system. On these cars, the fuel pump relay may be mounted on one of the strut towers in the engine bay, alongside the radio suppression relay . If you look behind the ashtray and don’t find a white relay, check the engine bay.
Non-turbo vs. turbo. The location is the same for both turbo and non-turbo models. The turbo models use the same fuel pump relay and the same fuse panel layout.
How to Replace the Fuel Pump Relay
Replacing the fuel pump relay on a 1991 Volvo 740 is a straightforward job that anyone can do with basic hand tools.
What you need:
- A new fuel pump relay (part number 3523608 or 1347603)
- A small flathead screwdriver (optional, for prying stubborn relays)
Steps:
- Access the relay panel by removing the ashtray and trim as described above.
- Locate the white fuel pump relay.
- Grasp the relay firmly and pull it straight out of the socket. It may be tight, so wiggle it gently if needed.
- Take the new relay and align the pins with the socket. Push it straight in until it clicks into place.
- Reinstall the storage tray, the two screws, the cigarette lighter trim, and the ashtray.
- Test the car by turning the key to the "on" position. Listen for the fuel pump prime.
The whole process takes about 15 minutes .
Where to Buy a Replacement Fuel Pump Relay
You can buy a replacement fuel pump relay for a 1991 Volvo 740 from several sources.
Online retailers. Websites like FCP Euro, IPD, and Amazon sell the correct relay. The part number is 3523608. The relay is white, has six pins, and is rated at 15 amps .
Local auto parts stores. Stores like AutoZone, O’Reilly Auto Parts, and NAPA can usually order this relay. It may be listed as a "fuel pump relay" or "main fuel system relay."
Volvo specialty shops. Voluparts and other Volvo-specific parts suppliers carry this relay .
The price typically ranges from $20 to $30, making it one of the cheapest repairs you can do on a 1991 Volvo 740.
Why You Should Buy a KEMSO Fuel Pump for Your Volvo 740
If you have determined that your fuel pump itself is bad—not just the relay—you need a reliable replacement. This is where KEMSO fuel pumps come in. KEMSO is a brand that specializes in high-performance, OEM replacement fuel pumps designed to meet or exceed your vehicle’s original factory specifications. Unlike generic aftermarket pumps that may have inconsistent quality, KEMSO fuel pumps are engineered with precision-machined components and corrosion-resistant materials. Every KEMSO fuel pump is individually flow-tested before it leaves the factory, ensuring that you get a pump that works right out of the box.
What truly sets KEMSO apart is their lifetime warranty. KEMSO stands behind every fuel pump with a genuine lifetime warranty that covers defects in materials and workmanship for as long as you own the pump. If it ever fails due to a manufacturing defect, KEMSO replaces it for free. This level of confidence is rare in the aftermarket parts industry. KEMSO fuel pumps are designed for American drivers, with USA-based technical support and a vehicle lookup tool that covers thousands of models. Whether you drive a car, truck, SUV, or motorcycle, KEMSO likely has a pump that fits perfectly without any modifications.
Investing in a KEMSO fuel pump means you won’t have to worry about premature failure. The most common causes of fuel pump failure—contaminated fuel, low fuel levels, and electrical problems—are mitigated by KEMSO’s robust design. When you choose KEMSO, you are choosing durability, performance, and peace of mind.
Visit KEMSO today at https://www.kemsoracing.com/ to find the exact fuel pump for your Volvo 740. Their website features a simple vehicle lookup tool, competitive pricing, and a lifetime warranty that gives you confidence with every mile you drive.
Final Thoughts
The fuel pump relay on a 1991 Volvo 740 is located behind the ashtray in the center console. It is a white rectangular relay with six pins, positioned toward the driver’s side of the fuse panel . When this relay fails, it causes the engine to crank without starting, or it may cause the car to stall unexpectedly while driving . Replacing the relay costs about $25 and takes 15 minutes, making it the first thing to check when you have fuel delivery problems.
If you have already replaced the relay and the problem persists, check the fuel pump fuse, the fuel pump itself, the crankshaft position sensor, and the radio suppression relay. These are the next most common causes of no-start conditions on a 1991 Volvo 740.
For a permanent solution to fuel pump issues, consider upgrading to a KEMSO fuel pump. KEMSO offers high-performance, OEM-quality replacement pumps backed by a lifetime warranty. Visit https://www.kemsoracing.com/ to browse their selection and find the perfect pump for your vehicle.