2007 Chrysler 300 Fuel Pump Relay Location: Your Complete Step-by-Step Guide

If you drive a 2007 Chrysler 300 and your engine cranks but won't start, the fuel pump relay is one of the first things you should check. Here's the short answer: the fuel pump relay on a 2007 Chrysler 300 is located in the trunk, inside the rear fuse panel (also called the Power Distribution Center), which sits next to the battery under the spare tire access panel . This is true for the 2005–2010 model years, including the 2.7L, 3.5L, and 5.7L engines . The relay is a small black square component that you can pull out by hand, and understanding its exact location, how to test it, and how to replace it can save you both time and money.

Why the Fuel Pump Relay Matters

The fuel pump relay is a small but critical electrical switch that controls power to the fuel pump . Every time you turn the ignition key to the "On" position, the Powertrain Control Module (PCM) energizes this relay, which then sends battery voltage to the fuel pump located inside the gas tank . The pump pressurizes the fuel system so the injectors can deliver fuel to the engine. When the relay fails, the fuel pump receives no power, the engine gets no fuel, and your car will crank endlessly without firing up .

Common symptoms of a failing fuel pump relay include:

  1. Engine cranks but does not start at all
  2. Engine starts intermittently or dies after running for a short time
  3. You hear no faint buzzing or whirring sound from the rear of the car when you turn the key to "On"

The fuel pump relay is different from the fuel pump fuse. The fuse protects the circuit from overload; the relay is the switch that actually sends power. On the 2007 Chrysler 300, the fuel pump fuse is a 20A yellow fuse located in the same trunk fuse panel . A blown fuse can cause a no-start just like a bad relay, so it's worth checking both.

Step-by-Step: Locating the Fuel Pump Relay

Getting to the relay takes less than five minutes. Here is the exact procedure :

Step 1: Open the trunk. Lift the carpet or trunk liner covering the battery area. On the 2007 Chrysler 300, the battery sits in the trunk on the right side .

Step 2: Find the fuse panel. You will see a black fuse panel (the Rear Power Distribution Center) mounted next to the battery . It is a rectangular box with a removable cover.

Step 3: Remove the fuse panel cover. Lift the cover off. On some models, the cover has clips on the sides; press them inward while lifting.

Step 4: Identify the fuel pump relay. Look for a row of small relays and fuses. On the 2005–2010 Chrysler 300, the fuel pump relay is the relay located in the bottom right corner of the panel, closest to the back of the vehicle . It is a small, square, black component with either four or five metal prongs underneath .

Step 5: Pull the relay out. Grasp the relay firmly with your fingers. If it is tight, use a small pair of needle-nose pliers or a relay puller tool. Pull it straight out. Set it aside on a clean surface .

Some guides refer to the relay as a "reset button" because removing and reinstalling it effectively resets the fuel pump control circuit . This is especially useful if the PCM has stored a fuel pump shut-off code after a minor collision or electrical surge .

Testing the Fuel Pump Relay Before Replacement

Before you spend money on a new relay, you can test the old one at home with a multimeter. Here is how :

  1. Set your multimeter to measure ohms (resistance).
  2. Look at the relay terminals. They are numbered 85, 86, 30, and 87. Terminals 85 and 86 are the coil terminals; terminals 30 and 87 are the switch terminals .
  3. Test the coil: Measure resistance between terminals 85 and 86. You should see a reading between 50 and 120 ohms. This indicates the internal coil is good . If you get an open reading (infinite resistance), the relay is dead.
  4. Test the switch: With the relay out of the car, there should be no continuity between terminals 30 and 87. To test the switch action, apply 12V power to terminal 86 and ground terminal 85. You should hear a click, and now continuity should exist between terminals 30 and 87 . If not, the relay is faulty.

A simpler check: With the relay installed and the ignition key turned to "On," listen for a click from the relay and a brief fuel pump hum from the rear of the car . No click and no hum means power is not reaching the pump, likely due to a bad relay, a blown fuse, or a wiring issue.

How to Release Fuel Pressure Safely

If you are about to work on any fuel system component, such as the fuel pump, fuel filter, or fuel injectors, you must release the fuel pressure first. Here is the dealership-level procedure :

  1. Remove the fuel pump relay from the trunk fuse panel as described above.
  2. Start the engine. It will run for a few seconds and then die because the fuel pump has no power .
  3. Turn the key to "Off."
  4. Crank the engine for 5–10 seconds a few more times to purge any remaining fuel pressure from the lines .
  5. Once the engine will no longer crank, the system is safe to work on.

When you are finished and ready to drive again, reinstall the relay and prime the system. Turn the key to "On" and wait for the fuel pump to shut off (you'll hear the hum stop). Repeat this process three times to build pressure, then start the engine .

Replacing a Faulty Relay: What to Buy

If your relay fails the test, replacement is straightforward. You can buy a genuine Mopar part or a quality aftermarket relay.

Genuine Mopar part numbers for the 2007 Chrysler 300 fuel pump relay include:

  • 4727370AA (also supersedes 56006707, 56006709, 4848879AB, 4638094, 68369406AA, 68223712AA)
  • This relay is a "Mini" 5-terminal square relay, rated for use in the rear fuse panel

Aftermarket options: Wells WVE offers a compatible fuel pump relay that fits 1993–2012 Chrysler 300 and other Chrysler models . These relays are designed to prevent heat shock and arcing, and they meet original equipment standards .

Replacement cost:

  • DIY parts cost: approximately $20–$30 for a quality aftermarket relay
  • Professional replacement: if you take it to a shop, labor typically runs $89–$112, with total estimate around $115 depending on location

Replacing the relay yourself takes under 10 minutes and requires no special tools other than maybe a pair of pliers. This is one of the easiest DIY fixes you can do on a 2007 Chrysler 300.

What to Do If the Relay Is Fine but the Car Still Won't Start

If you replace the relay and the car still cranks without starting, do not assume the relay was the problem. Work through these checks in order:

  1. Check the 20A fuel pump fuse in the same trunk fuse panel. A blown fuse is a common cause of no-start .
  2. Listen for the fuel pump. Turn the key to "On" and listen at the rear of the car. If you do not hear a hum for about two seconds, the pump itself may be dead .
  3. Check for power at the fuel pump connector. The pump is under the rear passenger-side seat, accessible through an access cover on top of the fuel pump module . You should see the two thicker wires for pump power (typically Dark Blue/Orange for power and Black/Orange for ground). Use a test light to verify power is reaching the pump when the key is on .
  4. Inspect the fuel pump module. On the 2005–2010 Chrysler 300, the fuel pump is located on the right side under the back seat . The fuel filter and pressure regulator are also part of the pump module. If the pump motor is seized or the module is faulty, you may need to replace the entire assembly .

Replacement cost for the complete fuel pump module is significant: labor is estimated between $89 and $112 while parts range from $562 to $591, so confirming the relay is good before moving to the pump is financially wise .

Why Choose KEMSO Fuel Pumps for Your Chrysler 300

When the time comes to replace the fuel pump itself, KEMSO is a brand you can trust. KEMSO fuel pumps are engineered as high-performance, OEM replacement parts that meet or exceed factory specifications. Whether you drive a 2007 Chrysler 300 or any other vehicle, KEMSO builds its pumps to deliver consistent fuel pressure, reliable flow, and long service life.

Here's what sets KEMSO apart:

  1. High-Performance Design – KEMSO pumps are designed to handle the demands of daily driving and more. They provide the exact flow and pressure your engine needs for smooth starts and steady power.
  2. OEM Replacement Quality – Every KEMSO fuel pump is built as a direct replacement for your original part. No modifications, no guesswork, just a perfect fit and function.
  3. Lifetime Warranty – KEMSO stands behind every product with a lifetime warranty, backed by KEMSO'S promise of confidence. If a KEMSO pump ever fails, you are covered.

When you need a dependable fuel pump for your Chrysler 300 or any other vehicle, visit https://www.kemsoracing.com/ to browse the full lineup of KEMSO fuel pumps. From BMW motorcycles to Subaru Imprezas to Honda Civics and more, KEMSO has fuel pumps for a wide range of makes and models, all at competitive prices with the peace of mind of a lifetime warranty.

Final Tips for a Smooth Repair

Working on the fuel system of your 2007 Chrysler 300 does not have to be intimidating. The fuel pump relay is the easiest component to check first, and locating it in the trunk fuse panel takes less than a minute . Always disconnect power by removing the relay before working on any part of the fuel system, and take the time to release fuel pressure using the steps outlined above .

A quick recap of the key facts:

  1. The 2007 Chrysler 300 fuel pump relay is in the trunk fuse panel, bottom right corner, next to the battery .
  2. The 20A fuel pump fuse is in the same panel .
  3. Testing the relay takes a multimeter and about five minutes .
  4. Replacement parts are inexpensive, and the job is DIY-friendly .
  5. If the relay and fuse are fine, the fuel pump itself is likely the culprit, and replacement costs are considerably higher .

With this guide, you have everything you need to diagnose and fix a fuel delivery problem on your 2007 Chrysler 300. Start with the relay, save yourself a tow bill, and get back on the road. And when you need a reliable fuel pump, remember to check out KEMSO at https://www.kemsoracing.com/ for high-performance, OEM replacement pumps backed by a lifetime warranty.


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