1991 Volvo 240 Fuel Pump Relay Location: Your Complete Guide to Finding and Fixing It

If your 1991 Volvo 240 cranks but won’t start, and you don’t hear the fuel pump hum for a second when you turn the key to the ON position, the fuel pump relay is the first thing to check. On a 1991 Volvo 240, the fuel pump relay is located behind the glove box on the passenger side of the dashboard.

This is a common failure point on these cars, and knowing exactly where it is and how to test it can save you hours of frustration and a costly tow bill. Here’s everything you need to know.

Where Is the Fuel Pump Relay on a 1991 Volvo 240?

The fuel pump relay on a 1991 Volvo 240 is located behind the glove box on the passenger side . To access it, you need to remove the glove box. Here’s the step-by-step process:

  1. Open the glove box fully.
  2. Locate the seven screws that hold the glove box in place around its outer edge .
  3. Remove all seven screws. The glove box will then pull straight out.
  4. Behind the glove box, you will see several relays mounted on a bracket. The fuel pump relay is the square one . It is typically white or green in color, depending on the replacement part .
  5. The relay is spring-clipped into a holding bracket and plugged into the wiring harness. To remove it, simply unclip the relay from the bracket and unplug it from the connector .

Important note: The round relay you may see nearby is for the bulb failure warning system, not the fuel pump . Make sure you are grabbing the square relay.

What Does the Fuel Pump Relay Do?

The fuel pump relay controls the operation of the fuel pumps . On a Volvo 240, there are two fuel pumps: one in the tank (the pre-pump) and one under the car (the main booster pump) . The relay is controlled by the ECU (Engine Control Unit) or the ignition circuit, depending on the model . Its job is to:

  • Power the fuel pumps when the ignition is turned on.
  • Shut the pumps off if the engine stops running, which is a safety feature .

When you turn the key to the ON position, the relay should click, and you should hear the fuel pumps run for about one second before they shut off . If you don’t hear that click or the pump hum, the relay is a prime suspect.

Why Does the Fuel Pump Relay Fail?

The fuel pump relay on the Volvo 240 is a known weak point . The most common failure is overheating of the main 12V power connection inside the relay, which causes the solder joint to fail . This is often caused by a failing pre-pump in the gas tank .

When the pre-pump starts to fail, the main fuel pump under the car has to work much harder, drawing excessive amperage. This extra current overheats the relay circuit, eventually causing it to fail . This is why simply replacing the relay without checking the pre-pump might only provide a temporary fix.

Symptoms of a Bad Fuel Pump Relay

If your fuel pump relay is failing, you may notice one or more of these symptoms:

  1. Intermittent no-start: The car starts fine sometimes, but other times it cranks indefinitely without firing .
  2. Engine stalls while driving: The car may run for a while and then suddenly die, especially after the engine is warm .
  3. No fuel pump noise: When you turn the key to the ON position, you do not hear the fuel pump prime for one second .
  4. Car restarts after cooling down: If the relay is overheating internally, it may work again once it cools off, leading to intermittent problems .

How to Test the Fuel Pump Relay

Before you buy a new relay, you can test the existing one. Here’s how:

Method 1: The Tap Test
If the car won’t start, tap the fuel pump relay with the handle of a screwdriver while someone turns the key to the ON position . If the car starts, the relay is likely bad, and the tap was enough to temporarily close the internal contacts. This is a temporary fix, not a permanent solution.

Method 2: Listen for the Click
With the glove box removed, have someone turn the key to the ON position. Listen for a distinct click from the relay . If you hear the click but the pumps don’t run, the relay may be working, but the wiring or the pumps themselves could be the issue.

Method 3: Bypass the Relay
You can bypass the relay to see if the fuel pumps work. This is a great way to confirm the relay is the problem. On a 1991 Volvo 240, you can jump Fuse #4 to Fuse #6 in the fuse box . The fuse box is located in the passenger footwell in front of the left front door pillar .

  • Use a piece of wire with stripped ends or a straightened paper clip.
  • Insert one end into the slot for Fuse #4 and the other end into the slot for Fuse #6 .
  • Turn the key to the ON position. If the fuel pump under the car starts humming loudly, the relay is bad .
  • Important: Disconnect the jumper wire after testing. If you drive with the jumper in place, the fuel pump will run continuously, even after you turn off the ignition, which could drain the battery .

Fuse Box Location and Related Fuses

The fuse box for the passenger compartment is located in front of the left front door pillar, on the driver’s side kick panel . It has a plastic cover that you remove by turning a fixing at the bottom 90 degrees .

For the fuel system, the key fuse to know is Fuse #6, which is a 16A fuse for the main fuel pump relay . This fuse is known to be a common problem area. On older Volvo 240s, the original fuses were ceramic, but many have been replaced with plastic-bodied fuses. Plastic fuses can overheat and cause breakdowns . It is good practice to check Fuse #6 regularly and replace it yearly, regardless of condition . If you have plastic fuses, consider replacing them with the original ceramic style for better reliability .

Other Possible Causes of a No-Start

If the fuel pump relay is fine and the fuse is good, there are a few other things to check on a 1991 Volvo 240:

  • Fuel Pump: The main booster pump is located under the car, just beneath the left rear passenger seat . The in-tank pre-pump is inside the fuel tank. If the pre-pump fails, the main pump has to work harder, which can lead to failure of both the relay and the main pump .
  • Crank Position Sensor: This sensor tells the ECU that the engine is rotating. If it fails, the ECU will not send power to the fuel pumps. The sensor is located on top of the bell housing where the engine and transmission meet . Check the wires for cracks or fraying.
  • ECU (Engine Control Unit): On some early LH 2.4 systems, the ECU itself can fail. The ECU is located behind the passenger side kick panel . If you have a pink-labeled ECU, it is known to be problematic and can be replaced with a newer version from a later model 940 .
  • Fuel Pressure Regulator: If the fuel pressure regulator fails, it can cause flooding and no-start conditions. It is located between the throttle body and the fuel distribution pipe .

Recommended Replacement: KEMSO Fuel Pump

If you have diagnosed the issue and determined that the fuel pump itself needs to be replaced, you need a reliable, high-performance replacement. We recommend the KEMSO brand Fuel Pump. KEMSO fuel pumps are built to meet or exceed OEM specifications, ensuring a perfect fit and reliable operation for your 1991 Volvo 240. They are designed for high performance and come with a lifetime warranty, giving you peace of mind on the road.

Stop wasting time with unreliable parts. Choose KEMSO for a fuel pump that will last. Visit their website to find the right fuel pump for your Volvo 240:

https://www.kemsoracing.com/

Summary

For a 1991 Volvo 240, the fuel pump relay is behind the glove box on the passenger side. It is a square, white or green relay. If your car has intermittent no-start issues or stalls while driving, this relay is the most likely culprit. Always check the related fuse, Fuse #6, in the driver’s side fuse box first. If you need a new fuel pump, consider a KEMSO fuel pump for a reliable, long-lasting solution. You can find their products at https://www.kemsoracing.com/.


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