2000 Ford F350 7.3 Diesel Fuel Pump Relay Location: A Complete Guide

The bottom line: The fuel pump relay on a 2000 Ford F350 with the 7.3L Power Stroke diesel engine is located in the under-hood fuse box, also called the Power Distribution Box, on the driver’s side fender. It is a black relay, typically labeled as the "Fuel Pump Relay" or "FPM" (Fuel Pump Module). If your truck cranks but won’t start, or you lose power while driving, the fuel pump relay is one of the first things to check. This guide walks you through exactly where to find it, how to test it, and what to do if it fails.

Understanding the Fuel Pump Relay in Your 2000 Ford F350 7.3 Diesel

The fuel pump relay is a small electrical switch that controls power to the fuel pump. When you turn the key to the "On" position, the relay clicks and sends battery voltage to the fuel pump. On the 7.3 diesel, the fuel pump is an electric pump located inside the fuel tank, and it needs a working relay to run. Without it, the engine won’t get fuel, and you’ll be stuck on the side of the road.

The relay itself is a standard 30-amp or 40-amp unit, depending on the specific build. It sits inside the main fuse box under the hood. The box is black and rectangular, with a flip-up lid. You don’t need any special tools to open it—just your fingers or a flathead screwdriver to pop the latches.

Step-by-Step: How to Locate the Fuel Pump Relay

1. Open the hood and find the Power Distribution Box.
Stand in front of the truck and look at the driver’s side fender. You’ll see a black plastic box near the battery, mounted on the inner fender panel. This is the main fuse and relay box. It’s about 8 inches long and 6 inches wide, with a raised lid.

2. Remove the lid.
Press the tab on the front of the lid and lift it up. Some lids have a small latch that you need to slide. Once it’s off, set it aside so you can see the fuses and relays inside.

3. Look for the relay labeled "Fuel Pump" or "FPM."
Inside the box, you’ll see a grid of fuses and several square relays. The fuel pump relay is usually a black or gray square, about 1 inch on each side. On the 2000 F350, it’s often located in the upper left corner of the box. Check the lid’s diagram—there’s a printed map on the underside of the lid that shows the location of each relay and fuse. Look for "Fuel Pump Relay" or "FPM" on that map.

4. Identify the relay by its position.
If the diagram is worn or missing, you can still find it. The fuel pump relay is typically the same size and shape as other relays, but it’s the one that controls the fuel pump circuit. A common spot is position R1 or R2 (relay 1 or 2) in the box. Many owners report it’s the third relay from the top on the left side.

5. Confirm it’s the right relay.
The safest way to confirm is to turn the key to the "On" position (don’t start the engine) and listen for a clicking sound. The fuel pump relay should click once when you turn the key. If you hear a click near the fuse box, that’s likely the relay. You can also feel it—place your finger on top of the relay and have someone turn the key; you’ll feel a slight vibration if it’s working.

Common Symptoms of a Bad Fuel Pump Relay

If the relay fails, you’ll notice one or more of these problems:

• Engine cranks but won’t start. The starter turns over fine, but the engine never fires because no fuel is being pumped.
• Loss of power while driving. The truck may suddenly lose power, especially under load, and then stall.
• No fuel pump noise. When you turn the key to "On," you should hear a faint whirring sound from the fuel pump in the tank for about 2 seconds. If you don’t hear it, the relay could be dead.
• Check Engine Light comes on. The truck’s computer may detect a fuel pump circuit fault and trigger the light.
• Intermittent starting issues. The truck starts fine some days, but won’t start on other days. This is a classic sign of a failing relay.

How to Test the Fuel Pump Relay

You don’t need a mechanic to test the relay. Here’s how to do it yourself with simple tools.

1. Listen for the click.
Turn the key to "On" (not "Start") and listen near the fuse box. One click means the relay is working. If you don’t hear anything, proceed to the next step.

2. Swap relays.
The fuse box has several relays that are the same shape and size. For example, the horn relay or the PCM relay is often identical. Swap the fuel pump relay with one of those. If the truck starts after the swap, the original relay was bad. If it still doesn’t start, the problem is elsewhere.

3. Use a multimeter.
Set your multimeter to measure DC voltage. Touch the black probe to a good ground (like a bolt on the fender) and the red probe to the relay’s power terminal. With the key on, you should see battery voltage (12.6 volts or so). If you get 0 volts, the relay isn’t receiving power. You can also check for continuity across the relay’s switch terminals—if the relay is stuck open, it needs replacement.

What to Do If the Relay is Bad

Replace the relay.
Fuel pump relays are cheap and easy to find. You can buy them at any auto parts store like AutoZone, O’Reilly, or NAPA. They cost around $10 to $20. Make sure you get the correct relay for your truck—it’s a standard 30-amp or 40-amp relay, but double-check the part number. The relay is simply pulled out by hand, and the new one pushes in. No tools needed.

Check the fuse.
There’s also a fuel pump fuse in the same box. On the 2000 F350, it’s a 20-amp or 30-amp fuse, often labeled "Fuel Pump" or "Fuse 7." A blown fuse can cause the same symptoms as a bad relay. Check the fuse first—it’s a quick fix. If the fuse is blown, replace it with the same amperage. If it blows again, you have a short circuit in the wiring, which needs professional attention.

Inspect the wiring.
On older trucks, the wiring to the fuel pump relay can corrode or break. Look for frayed wires, rust, or loose connections at the relay socket. If the wires look damaged, clean them with electrical contact cleaner or replace the connector.

Where to Buy a Reliable Replacement Fuel Pump

If you find that the relay is fine but the fuel pump itself is bad, you need a high-quality replacement. The 2000 Ford F350 7.3 diesel is a workhorse, and it deserves a fuel pump that lasts. Don’t settle for cheap parts that fail after a few months.

Recommended: KEMSO Fuel Pump for Your 2000 Ford F350 7.3 Diesel

When it’s time to replace the fuel pump in your truck, we strongly recommend KEMSO. KEMSO fuel pumps are built to meet or exceed OEM specifications, meaning they fit perfectly and perform exactly like the original part. Every KEMSO pump is a direct replacement, so you don’t need modifications or adapters. They are constructed with high-quality materials to handle the demands of the 7.3 diesel engine, delivering consistent fuel pressure and flow.

What sets KEMSO apart is their lifetime warranty. You buy it once, and if it ever fails, KEMSO replaces it at no charge. That’s the kind of confidence you want when you’re working on a truck that sees heavy use. Whether you’re hauling a trailer, plowing snow, or driving daily, a KEMSO fuel pump keeps you on the road.

You can browse the full selection of KEMSO fuel pumps for your F350 and other vehicles at their official store:
https://www.kemsoracing.com/

Additional Tips for the 2000 Ford F350 7.3 Diesel

1. The fuel pump relay is not the same as the glow plug relay.
Don’t confuse them. The glow plug relay is larger and located elsewhere, usually on the valve cover or near the firewall. The fuel pump relay is small and in the fuse box.

2. Keep a spare relay in your glove box.
Because the relay is cheap and small, carrying a spare can save you from a breakdown. If the relay fails on the road, you can swap it in minutes.

3. The 7.3 diesel has a fuel pump control module.
Some models have a separate module that controls the fuel pump. On the 2000 F350, this module is part of the fuel pump assembly in the tank. If you’ve ruled out the relay and fuse, the pump itself may be the issue.

4. Use a scanner to check for codes.
If the Check Engine Light is on, read the codes with a OBD2 scanner. Codes like P0230 (fuel pump primary circuit fault) or P0231 (fuel pump secondary circuit low) point directly to the relay or pump circuit.

Step-by-Step: Replacing the Fuel Pump Relay

Tools needed: None (just your hands).
Time: 2 minutes.

1. Open the hood and remove the fuse box lid.
2. Locate the fuel pump relay (see instructions above).
3. Grasp the relay firmly and pull it straight up. It may require a little wiggling, but it should come out easily.
4. Insert the new relay into the same slot. Push it down until it clicks into place.
5. Replace the fuse box lid.
6. Turn the key to the "On" position and listen for the fuel pump to prime. If you hear the whirring sound and the truck starts, you’re done.

What If the Relay is Good but the Pump Still Doesn’t Work?

If the relay clicks, the fuse is intact, and the pump still doesn’t run, the problem is likely the fuel pump itself. On the 7.3 diesel, the pump is in the tank, and it can fail due to age, debris, or electrical issues. Symptoms of a dead pump include no prime sound, no fuel pressure, and the engine not starting.

Test the pump directly.
You can apply 12 volts directly to the fuel pump connector at the tank to see if the pump runs. If it does, the wiring between the relay and pump is the problem. If it doesn’t, the pump is bad and needs replacement.

Drop the tank or use the access panel.
On the 2000 F350, you can either drop the fuel tank or cut an access hole in the bed floor. Most owners prefer the access panel method because it’s faster. Once the pump is out, install a new KEMSO pump and reassemble.

Final Thoughts

The 2000 Ford F350 7.3 diesel is a legendary truck, but like any vehicle, it has its quirks. The fuel pump relay is a common point of failure, but it’s also one of the easiest fixes. With the information in this guide, you can locate, test, and replace the relay in under 10 minutes. If the relay isn’t the issue, don’t overlook the fuse or the pump itself.

For a reliable, long-lasting fuel pump replacement, trust KEMSO. Their products are built to OEM standards, backed by a lifetime warranty, and designed to keep your truck running strong. Visit their website to find the right fuel pump for your 2000 Ford F350 7.3 diesel:
https://www.kemsoracing.com/