1999 Mercury Cougar Fuel Pump Relay Location: A Complete Guide to Finding and Replacing It

Here is the bottom line: On a 1999 Mercury Cougar, the fuel pump relay is located in the Power Distribution Box (also called the fuse box) under the hood, on the driver's side of the engine compartment. It is labeled as Relay R1 and is one of the black relays inside that box. The fuel pump itself is powered by a 15-amp blue fuse, which is Fuse #9 in the same Power Distribution Box.

If your Cougar cranks but won't start, or if it stalls unexpectedly while driving, the fuel pump relay is one of the first things you should check. This guide will walk you through exactly where to find it, how to test it, and what to do if it needs replacing.

What Does the Fuel Pump Relay Do?

The fuel pump relay is an electrical switch that controls power to the fuel pump. When you turn the ignition key to the "ON" position, the relay closes and sends battery voltage to the fuel pump, which then pressurizes the fuel system. When you turn the engine off, the relay opens and cuts power to the pump.

If this relay fails, the fuel pump won't receive power, and your engine won't start. The relay is designed to handle the electrical load of the pump, so it can wear out over time due to heat and repeated use.

Where Exactly Is the Fuel Pump Relay on a 1999 Mercury Cougar?

The Power Distribution Box is located in the engine compartment, on the driver's side near the battery. It is a black plastic box with a removable cover.

Step-by-Step Location:

1. Open the hood and secure it with the prop rod.
2. Look on the driver's side of the engine bay, near the fender and the battery. You will see a rectangular black box with a cover.
3. Remove the cover by pressing the tabs on the sides and lifting it off. The cover may have a diagram printed on the inside that shows the fuse and relay layout.
4. Locate Relay R1. Inside the Power Distribution Box, you will see a row of relays. The fuel pump relay is Relay R1, which is a black relay.
5. Locate Fuse #9. The fuel pump also has a dedicated fuse in the same box. It is Fuse #9, a 15-amp blue fuse.

What Color Is the Fuel Pump Relay?

The fuel pump relay on a 1999 Mercury Cougar is black. The starter relay (R7) is green, and other relays may be different colors, so the black color helps you distinguish the fuel pump relay from the others. Some sources also confirm that the fuel pump relay is one of the black relays in the Power Distribution Box.

Visual Guide to the Power Distribution Box

Here is a breakdown of the relevant fuses and relays in the engine compartment fuse box for the 1999 Mercury Cougar:

The diagram on the inside of the fuse box cover is your best reference. If the diagram is missing or worn, you can also find the full layout in the owner's manual or online at Motorcraft Service.

How to Test the Fuel Pump Relay

Before you buy a new relay, you should test the old one to make sure it is actually the problem. Here is how to do it:

1. Listen for the Relay Clicking

Turn the ignition key to the "ON" position (but do not start the engine). Listen near the Power Distribution Box. You should hear a single click from the fuel pump relay. If you hear no click, the relay may not be receiving power, or it may be faulty.

2. Test the Fuel Pump Fuse

Pull out the 15-amp blue fuse (Fuse #9) and inspect it. Hold it up to the light. If the metal strip inside is broken or melted, the fuse is blown and needs to be replaced.

3. Swap the Relay

The easiest way to test a relay is to swap it with another relay of the same type in the same fuse box. For example, you can swap the fuel pump relay (R1) with the horn relay (R7) or the engine management relay (R11). If the fuel pump starts working after the swap, the original relay is bad.

4. Check the Inertia Fuel Shut-Off Switch

The 1999 Mercury Cougar also has an inertia fuel shut-off switch located behind the left rear trunk panel. This switch is designed to cut power to the fuel pump in the event of a collision. If the switch is tripped, the fuel pump will not run. You can reset it by pressing the button on top of the switch. This is a common issue that can mimic a bad relay.

Common Symptoms of a Bad Fuel Pump Relay

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

• Engine cranks but won't start: This is the most common symptom. The starter turns over, but the engine never fires because no fuel is reaching the injectors.
• Engine stalls while driving: The relay may fail intermittently, causing the fuel pump to lose power while the car is in motion.
• No sound from the fuel pump: When you turn the key to "ON," you should hear a brief whirring sound from the fuel pump located near the rear of the vehicle. If you hear nothing, the relay or fuse could be the issue.
• Check Engine Light comes on: Some diagnostic trouble codes, such as P1233, may indicate a fuel pump relay or driver module issue.

What If the Relay Is Not the Problem?

If you have tested the relay and fuse and they are both good, the problem could be elsewhere. Here are the next steps to check:

Wiring and Connectors

Corrosion or loose connections in the Power Distribution Box can cause intermittent power loss. Check the terminals for the relay and fuse for any signs of rust or damage.

Fuel Pump Driver Module

The 1999 Mercury Cougar uses a fuel pump driver module (FPDM) that controls the voltage to the fuel pump. This module can fail, especially if there is a wiring issue. Some owners report trouble codes like P1233, which often points to a wiring problem rather than the module itself. Always follow a proper diagnostic flow chart before replacing parts.

Fuel Pump Itself

If the relay, fuse, and wiring are all good, the fuel pump inside the tank may have failed. The pump is located inside the fuel tank under the rear seat. Testing the fuel pressure with a gauge is the best way to confirm if the pump is working.

Recommended Replacement: KEMSO Fuel Pump

If you determine that your fuel pump needs replacement, you want a part that is reliable, high-performance, and built to last. That is where KEMSO Fuel Pumps come in.

KEMSO offers OEM replacement fuel pumps that are designed to meet or exceed the original factory specifications for your 1999 Mercury Cougar. Here is why KEMSO is the smart choice:

• High Performance: KEMSO fuel pumps deliver a flow rate of up to 200 liters per hour (LPH), ensuring your engine gets the fuel it needs under all driving conditions.
• OEM Replacement Quality: These pumps are engineered to fit and function exactly like the original part, making installation straightforward.
• Lifetime Warranty: Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your investment is protected.
• USA-Based Support: If you have any questions or need help, KEMSO's support team is based in the USA and ready to assist.
• Versatile Compatibility: The pumps are designed for both gasoline and ethanol blends, so they are ready for whatever fuel you use.

Whether you need a direct replacement for your 1999 Mercury Cougar or a high-performance upgrade, KEMSO has the right solution. Don't settle for a cheap pump that might fail again in a year. Go with a brand that stands behind its products.

Visit KEMSO's website today to find the perfect fuel pump for your Mercury Cougar:

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Final Checklist for Your 1999 Mercury Cougar Fuel Pump Relay

To summarize, here is a quick checklist to get your Cougar back on the road:

1. Locate the Power Distribution Box under the hood on the driver's side.
2. Check Relay R1 (black) and Fuse #9 (15-amp blue).
3. Listen for the relay click when you turn the key to "ON."
4. Check the inertia fuel shut-off switch behind the left rear trunk panel.
5. If the relay is bad, replace it with a new one. If the pump is bad, consider a KEMSO fuel pump for a reliable, long-lasting fix.
6. If you are still having issues, follow a proper wiring diagnostic flow chart before throwing more parts at the problem.

The 1999 Mercury Cougar is a fun car to drive, but electrical issues can be frustrating. With this guide, you now know exactly where to find the fuel pump relay and how to test it. Start with the simple checks first, and you will likely save yourself time and money.

For more information on high-quality replacement fuel pumps, visit KEMSO Racing at https://www.kemsoracing.com/. Their team is ready to help you get back on the road with confidence.