1999 Ford Ranger Fuel Pump Relay: Location, Symptoms, and How to Fix It

If your 1999 Ford Ranger cranks but won’t start, or if it stalls while driving, the fuel pump relay is often the first thing to check. This small, inexpensive part controls power to the fuel pump, and when it fails, your engine gets no fuel. The relay is located in one of two places depending on your Ranger’s engine and trim: either under the hood in the power distribution box (fuse box) or inside the cabin in the central junction box under the dashboard. Knowing exactly where to find it, how to test it, and how to replace it can save you a tow bill and a trip to the mechanic. This guide walks you through the entire process, step by step.

Where Is the Fuel Pump Relay Located?

The 1999 Ford Ranger has two possible locations for the fuel pump relay, and the correct one depends on your specific model. Here is what you need to know:

For most 1999 Rangers with the 3.0L V6 engine, the fuel pump relay is inside the cabin. It is located in the Central Junction Box (CJB), which is the fuse panel under the dashboard on the driver’s side. Specifically, it is in relay position R6 . To access it, sit in the driver’s seat, look down and to the left of the steering column, and you will see a rectangular plastic cover panel. Pull it straight toward you to remove it—no tools are needed. Inside, you will see rows of relays and fuses. Look for the slot labeled “R6” on the circuit board .

For other 1999 Ranger models, the fuel pump relay is under the hood. It is located in the power distribution box (PDB), which is the main fuse box near the battery on the driver’s side fender well . Open the hood and locate the black plastic box next to the battery. Remove the lid by pressing the release tabs. Inside, the fuel pump relay is typically in slot #5 . The relay itself is a small, square, black or blue plastic component about an inch wide . If you are unsure, check the diagram printed on the underside of the fuse box lid—it will show you exactly which relay is which.

Quick tip: If you have a 3.0L engine, start by checking under the dashboard first. If you have a different engine (like the 2.5L or 4.0L), start under the hood. When in doubt, look at the diagram on the fuse box cover under the hood—it is the most reliable guide for your specific truck .

Common Symptoms of a Bad Fuel Pump Relay

A failing fuel pump relay usually gives you clear warning signs. Here are the most common ones to watch for:

  1. Engine cranks but won’t start. This is the most obvious symptom. When you turn the key, the starter motor turns the engine over normally, but the engine never fires up because no fuel is reaching it . This happens when the relay fails to send power to the fuel pump.

  2. No fuel pump priming sound. When you turn the ignition key to the “ON” position (without starting the engine), you should hear a brief humming or buzzing sound from the rear of the truck for about 2 to 3 seconds. That is the fuel pump pressurizing the fuel system. If you hear nothing, the relay is likely not sending power to the pump .

  3. Intermittent stalling while driving. The truck may run fine for a while, then suddenly lose power and stall, especially when the engine is warm. This can happen because the relay overheats and temporarily fails. After the truck cools down for a few minutes, it may restart and run again .

  4. Difficulty starting. The engine might take longer than usual to start, requiring you to crank it for several seconds before it catches. This is a sign that the relay is working intermittently .

  5. Clicking sound from the fuse box. If you hear a rapid clicking noise coming from the area of the fuse box when you turn the key, it often means the relay is trying to engage but failing to make a solid connection .

How to Test the Fuel Pump Relay

You do not need a lot of tools or mechanical experience to test the fuel pump relay. Here are three simple methods:

Method 1: The Swap Test (Easiest)
This is the quickest way to check if the relay is bad. Find an identical relay in the same fuse box—the horn relay or the A/C relay are usually the same size and shape. Pull out the fuel pump relay and swap it with the horn relay . Then, try to start the truck. If the engine starts now, the original fuel pump relay was faulty. (Note: your horn will not work until you replace the relay.) If the truck still does not start, the problem is likely elsewhere .

Method 2: Visual Inspection
Remove the relay from its socket and look at it closely. Check for any signs of damage: cracks in the plastic, burnt or melted terminals, or corrosion on the metal prongs . If you see any of these, replace the relay immediately.

Method 3: Multimeter Test
If you have a multimeter, you can test the relay more precisely. First, check the fuel pump fuse (fuse #9, 20-amp mini-fuse in the under-hood fuse box) to make sure it is not blown . If the fuse is good, remove the relay. Set your multimeter to measure resistance (ohms). Touch the probes to the two coil terminals (usually pins 85 and 86 on the relay). You should see a reading between 50 and 120 ohms. If you get infinite resistance (OL), the relay coil is open and the relay is bad. Next, apply 12V power to the coil terminals (using a battery or a 12V power supply) and listen for a click. While power is applied, check for continuity between the switch terminals (pins 30 and 87). If you have continuity when power is applied, the relay is working. If not, it is faulty .

How to Replace the Fuel Pump Relay

Replacing the fuel pump relay is a straightforward job that takes about 10 minutes. Here is how to do it:

Step 1: Disconnect the battery. Always disconnect the negative battery terminal before working with electrical components. This prevents accidental shorts .

Step 2: Locate and remove the relay. Using the information above, find the relay in the correct location (under the hood or under the dashboard). Pull it straight out of its socket. You can use a relay puller tool or a small flathead screwdriver to gently pry it out. Be careful not to damage the socket .

Step 3: Install the new relay. Take your new relay (Ford part number F5TZ-14B192-A or an equivalent aftermarket relay) and push it firmly into the same socket until it clicks into place . Make sure it is fully seated.

Step 4: Reconnect the battery. Reattach the negative battery terminal and tighten it securely.

Step 5: Test the repair. Turn the ignition key to the “ON” position. You should hear the fuel pump prime for a few seconds. Then, start the engine. If it starts and runs normally, the repair is successful.

What Else to Check If the Relay Is Not the Problem

If you replace the fuel pump relay and the truck still does not start, there are a few other things to check before assuming the fuel pump itself is bad:

Fuel pump fuse. Check fuse #9 in the under-hood power distribution box. It is a 20-amp mini-fuse that protects the fuel pump relay and the RAP module . If it is blown, replace it. If it blows again immediately, there is a short circuit somewhere in the fuel pump wiring.

Fuel pump inertia switch. This is a safety switch that cuts power to the fuel pump in the event of a collision. On the 1999 Ford Ranger, it is located in the right front passenger footwell, near the kick panel . If it has been tripped, press the reset button on top of it.

Fuel pump itself. If the relay and fuse are good, and the inertia switch is not tripped, the fuel pump inside the gas tank may have failed. You can test this by listening for the pump when you turn the key to “ON.” If you hear nothing, the pump may need to be replaced.

Final Thoughts

The fuel pump relay on a 1999 Ford Ranger is a simple, inexpensive part that can cause big problems when it fails. Whether it is located under the hood in the power distribution box or under the dashboard in the central junction box, knowing how to find it, test it, and replace it will save you time and money. Start with the swap test—it is the fastest way to know if the relay is the culprit. If the relay checks out, move on to the fuse and the inertia switch before replacing the fuel pump itself.

Recommended Fuel Pump Upgrade: KEMSO Fuel Pump

If you find that your fuel pump needs replacement, or if you simply want a reliable, high-quality upgrade, consider the KEMSO Fuel Pump for your Ford Ranger. KEMSO is a leading brand in the aftermarket fuel pump industry, and their products are designed to meet or exceed OEM specifications. Every KEMSO fuel pump is a high-performance, OEM replacement part, meaning it fits exactly like the factory pump and delivers the same—or better—performance. Best of all, every KEMSO fuel pump comes with a lifetime warranty, so you can install it with confidence knowing it is built to last.

Whether you drive a Ford Ranger, a motorcycle, an ATV, or any other vehicle, KEMSO has a fuel pump that fits your needs. Visit their website to browse their full selection of fuel pumps, read customer reviews, and find the perfect replacement for your vehicle. Their commitment to quality and customer satisfaction makes them the go-to choice for DIY mechanics and professionals alike.

Visit KEMSO at: https://www.kemsoracing.com/

For more information on the 1999 Ford Ranger fuel pump relay, including detailed diagrams and troubleshooting tips, consult your owner’s manual or check the fuse box cover diagram under the hood. With the right information and a few basic tools, you can get your Ranger back on the road quickly and safely.

Visit KEMSO at: https://www.kemsoracing.com/


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