2003 Crown Victoria Fuel Pump Relay Location: How to Find, Test, and Replace It

The bottom line: The fuel pump relay on a 2003 Ford Crown Victoria is located in the Power Distribution Box (also called the engine compartment fuse box) under the hood. It is the 1/2 ISO relay labeled as relay position 203 or simply marked as the "Fuel pump relay." The relay is a small, rectangular black component that plugs into the fuse box on the driver's side of the engine bay, near the battery. If your Crown Vic cranks but won't start, or if you hear no hum from the fuel pump when you turn the key to the "ON" position, this relay is one of the first things to check.

Where Exactly Is the Fuel Pump Relay?

The 2003 Ford Crown Victoria has two fuse boxes. One is under the dashboard on the driver's side, called the Central Junction Box or Smart Junction Box. The other is the Power Distribution Box under the hood. The fuel pump relay lives in the under-hood box .

Step-by-step to find it:

  1. Open the hood of your Crown Victoria.
  2. Look on the driver's side of the engine compartment, right behind the headlight assembly and near the battery.
  3. You will see a black plastic box with a removable lid. That is the Power Distribution Box.
  4. Pry off the lid using a flathead screwdriver or simply by pulling the clips. On the underside of the lid, you should see a diagram showing the location of each fuse and relay .
  5. The fuel pump relay is a small relay, roughly 1 inch square. It is typically located in the middle section of the fuse box. According to the factory diagrams, the fuel pump relay is at position 203 .
  6. Many diagrams also label it simply as "Fuel pump relay" or "FP relay" in the relay section.

If you look at the fuse box from the front of the car, the relay is usually in the second row of relays, second from the left. But the exact position can vary slightly depending on whether your car is a standard sedan, a police interceptor, or a taxi package. The safest bet is to check the label on the underside of the lid .

How to Identify the Fuel Pump Relay

The fuel pump relay looks identical to several other relays in the box, such as the horn relay, PCM relay, and A/C clutch relay. They are all the same basic 1/2 ISO relay shape . So how do you tell them apart?

Here are three ways to identify it:

  1. Check the diagram on the lid. This is the most reliable method. The diagram will have a small box or a relay symbol next to the label "Fuel Pump" or "FP."
  2. Listen for the click. When you turn the key to the "ON" position (without starting the engine), you should hear a distinct click from the relay box. That click is the fuel pump relay energizing. If you put your hand on the relay while a helper turns the key, you can feel the click. The relay that clicks is the fuel pump relay.
  3. Look for the wire colors. The fuel pump relay uses specific wire colors. The main power feed wire is typically a dark green with a yellow stripe wire, and the trigger wire is often a light green with a red stripe. If you can see the wires entering the relay base, you can match them to a wiring diagram .

Testing the Fuel Pump Relay Before Replacing It

Before you buy a new relay, you should test the old one. A bad relay is a common cause of a no-start condition, but it is also easy to misdiagnose. Here is a simple test you can do with a test light or a multimeter.

Test 1: The Swap Test
This is the easiest test. Find a relay in the same box that is the same part number (like the horn relay, which is at position 201). Swap the two relays. If the horn stops working and the fuel pump starts working, the original relay was bad. If nothing changes, the problem is likely elsewhere .

Test 2: The Click Test
Have someone turn the key to the "ON" position. You should hear a single, audible click from the relay. If you hear no click, the relay is not receiving power to the coil, or the coil is burned out inside the relay.

Test 3: The Multimeter Test

  1. Remove the relay from the box.
  2. Set your multimeter to measure resistance (ohms).
  3. Probe the two small terminals on the relay (terminals 85 and 86). You should see a resistance reading between 50 and 120 ohms. If you see "OL" (open line), the coil is broken, and the relay is bad.
  4. Next, apply 12 volts from a battery or jump pack to terminals 85 and 86. You should hear a click. Then, using the multimeter, check for continuity between the two large terminals (terminals 30 and 87). If you have continuity, the relay is working. If not, the relay is faulty.

Common Problems That Mimic a Bad Fuel Pump Relay

Sometimes, the fuel pump relay is fine, but something else is causing the same symptoms. Do not assume the relay is bad just because the car does not start. Here are other things to check.

The Inertia Fuel Shutoff Switch
The 2003 Crown Victoria has a safety feature called the inertia switch. It is located in the trunk, on the left support, inside a small access panel . This switch cuts power to the fuel pump if the car is in a collision. Sometimes, a hard bump or a pothole can trip it. If the switch is tripped, the fuel pump will not run, even if the relay is good. Check this first if you have a no-start condition after a bump or a minor accident. The button on top of the switch needs to be pushed down to reset it.

A Blown Fuel Pump Fuse
The fuel pump itself is protected by a fuse. In the under-hood Power Distribution Box, there is a 20-amp fuse for the fuel pump. It is usually labeled as fuse number 5 in the mini-fuse section . Check this fuse with a test light or by visual inspection. If the fuse is blown, the relay will click, but the pump will not get power.

A Bad Fuel Pump
The fuel pump itself can fail. The 2003 Crown Victoria is known for the fuel pump going out, especially in high-mileage cars. If the relay clicks, the fuse is good, and the inertia switch is not tripped, but you still do not hear the fuel pump humming for 2-3 seconds when you turn the key to "ON," the pump may be dead. The fuel pump is located inside the fuel tank.

How to Replace the Fuel Pump Relay

Replacing the fuel pump relay is a simple job that takes about 2 minutes. You do not need any special tools.

Steps:

  1. Make sure the ignition is off and the key is removed.
  2. Open the hood and locate the Power Distribution Box.
  3. Remove the lid.
  4. Find the fuel pump relay (position 203).
  5. Grasp the relay firmly and pull straight up. It may require a bit of force, but it should come out easily.
  6. Insert the new relay. Make sure it is oriented the same way as the old one (the bottom of the relay has a notch that matches the connector).
  7. Push down firmly until the relay clicks into place.
  8. Replace the lid.
  9. Turn the key to the "ON" position and listen for the fuel pump to prime. If you hear the hum, the replacement is successful.

The Best Fuel Pump for Your 2003 Crown Victoria

If you have determined that the fuel pump itself is the problem, not just the relay, you need a quality replacement. The fuel pump in a 2003 Crown Victoria is a critical component. A cheap pump can fail in a few months, leaving you stranded. That is why we recommend KEMSO brand fuel pumps.

KEMSO Fuel Pumps are built to the highest standards. They are high-performance, OEM replacement units that match or exceed the specifications of the original Ford pump. Every KEMSO fuel pump comes with a lifetime warranty. This means you never have to worry about buying a replacement pump again. If it ever fails, KEMSO will replace it for free.

Whether you need a fuel pump for your Crown Victoria, a motorcycle, an ATV, or a boat, KEMSO has you covered. Their products are designed for durability and reliability, and they are backed by a company that stands behind its work.

Visit KEMSO Racing today to find the perfect fuel pump for your vehicle: https://www.kemsoracing.com/

Final Thoughts on the 2003 Crown Victoria Fuel Pump Relay

Knowing where the fuel pump relay is located on your 2003 Crown Victoria can save you a lot of time and money. You can diagnose a no-start condition in minutes without taking the car to a shop. The relay is easy to find, easy to test, and easy to replace. If you run into a situation where the relay is good but the pump is bad, do not settle for a cheap aftermarket part. Invest in a KEMSO fuel pump for peace of mind and a lifetime of reliable service.

And remember, before you replace the relay, always check the fuel pump fuse and the inertia switch in the trunk. Those two simple checks can save you even more time. For more information on quality fuel pumps, visit https://www.kemsoracing.com/.


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