2008 Dodge Charger Fuel Pump Relay: Symptoms, Location, and How to Replace It
The bottom line up front: If you own a 2008 Dodge Charger and you are dealing with hard starts, engine stalling, or a complete no-start condition, the 2008 Dodge Charger fuel pump relay is one of the first components you should check. This small but critical part controls the flow of electrical power to the fuel pump, and when it fails, your engine simply won't get the fuel it needs to run. The good news is that this is a relatively inexpensive part, typically costing around $30 to $55 for a genuine OEM unit, and you can often replace it yourself in under ten minutes without any special tools. This guide will walk you through everything you need to know about the fuel pump relay on your 2008 Charger, including where it is located, how to test it, the common symptoms of failure, and the exact steps to replace it.
What Does the Fuel Pump Relay Do in a 2008 Dodge Charger?
The fuel pump relay acts as an electrical switch that connects the battery's power to the fuel pump. When you turn the ignition key to the "ON" position, the relay closes and sends power to the fuel pump, which then pressurizes the fuel system so the engine can start. The relay also plays a safety role: in the event of a collision, the vehicle's computer can cut power through this relay to minimize the risk of a fire.
In the 2008 Dodge Charger, the fuel pump relay is not just a single-purpose part. The same relay type is used for several other functions in the vehicle, including the PCM (Powertrain Control Module) relay, fan relay, A/C clutch, starter, and fog lights. This means if you suspect a bad relay, you can often swap it with another identical relay in the fuse box to test whether it is the culprit.
Where Is the Fuel Pump Relay Located on a 2008 Dodge Charger?
The 2008 Dodge Charger has two main fuse boxes: one in the engine compartment and one in the luggage compartment (trunk). The fuel pump relay for the 2008 model year is located in the luggage compartment fuse box, which is found in the rear of the vehicle under the spare tire access panel. This is different from many other vehicles where the fuel pump relay is under the hood, so it is worth noting if you are used to working on other cars.
To access it:
- Open the trunk and remove the spare tire cover or access panel.
- Look for the fuse box, which is typically on the driver's side of the luggage compartment.
- Remove the fuse box cover to reveal the fuses and relays.
- Locate cavity number 6, which is designated for the 20A Fuel Pump fuse. The relay itself is typically positioned nearby, and the cover diagram will help you identify it.
Symptoms of a Failing Fuel Pump Relay
A failing fuel pump relay can produce a range of symptoms, some of which are similar to a failing fuel pump itself. Here are the most common signs to watch for:
1. Engine Cranks But Won't Start
This is the most classic symptom. If you turn the key and the engine cranks over fine, but it never fires up, the fuel pump relay might not be sending power to the fuel pump. You can test this by turning the key to the "ON" position (without cranking) and listening for a whirring sound from the rear of the car. If you don't hear the fuel pump prime, the relay could be dead.
2. Intermittent Stalling
If the relay is failing but not completely dead, you might experience random stalling while driving. The engine may cut out and then restart after a few minutes once the relay cools down or makes contact again. This is both frustrating and dangerous, especially on the highway.
3. No Fuel Pump Priming Sound
When you turn the ignition to "ON," you should hear a brief humming or whirring noise from the rear of the car. This is the fuel pump pressurizing the system. If you don't hear this sound, the relay is likely not sending power to the pump.
4. Hard Starting
If the relay is weak or has corroded contacts, it may not deliver full voltage to the fuel pump. This can result in longer cranking times before the engine starts, as the fuel system takes longer to pressurize.
5. Check Engine Light
While the check engine light alone doesn't confirm a bad relay, it may come on if the powertrain control module detects a fuel pressure issue. You might see codes related to a lean condition or fuel system malfunction.
How to Test the Fuel Pump Relay
Before you spend money on a new relay, you should test the existing one. There are two straightforward methods:
Method 1: The Swap Test
As mentioned earlier, the fuel pump relay in the 2008 Charger is the same type used for several other functions. Find an identical relay in the same fuse box (for example, the horn relay or a similar mini relay) and swap them. If the fuel pump starts working with the swapped relay, then your original relay was bad. If the swapped relay also fails to activate the pump, the problem may be elsewhere, such as the fuel pump itself or a wiring issue.
Method 2: Multimeter Test
If you have a multimeter, you can test the relay directly. Here's how:
- Remove the relay from the fuse box.
- Set your multimeter to the ohms setting.
- Check for continuity between the coil terminals (usually pins 85 and 86). You should see some resistance reading, typically between 50 and 120 ohms. If there's no reading (infinite resistance), the coil is open and the relay is dead.
- To test the switch contacts (pins 30 and 87), apply 12V power to the coil terminals. You should hear a click and see continuity between pins 30 and 87. If not, the relay is faulty.
How to Replace the 2008 Dodge Charger Fuel Pump Relay
Replacing the fuel pump relay is one of the easiest repairs you can do on this vehicle. Here's the step-by-step process:
Step 1: Gather Your Tools
You don't need much. Just a new relay (OEM part number 4727370AA) and possibly a pair of needle-nose pliers to help pull the old relay out. The new relay typically costs between $30 and $55 for a genuine Mopar part.
Step 2: Disconnect the Battery
Before working with any electrical components, disconnect the negative battery terminal to prevent any short circuits. This is a safety precaution that should never be skipped.
Step 3: Access the Relay
Open the trunk, remove the spare tire access panel, and locate the luggage compartment fuse box. Remove the cover to expose the relays.
Step 4: Remove the Old Relay
The relay should be a small black or gray cube. Grasp it firmly and pull it straight out. If it's stuck, gently rock it back and forth while pulling, or use needle-nose pliers to grip it.
Step 5: Install the New Relay
Line up the new relay with the socket and press it firmly into place. Make sure it sits flush with the fuse box. The relay is keyed, so it can only go in one way.
Step 6: Reconnect and Test
Reconnect the negative battery terminal. Turn the ignition to the "ON" position and listen for the fuel pump priming sound. If you hear it, the replacement was successful.
What If the Relay Isn't the Problem?
If you replace the relay and the fuel pump still doesn't work, there are a few other components to check:
1. The Fuel Pump Fuse
Check the 20A fuel pump fuse in the luggage compartment fuse box (cavity 6). If this fuse is blown, the fuel pump won't receive power regardless of the relay's condition. Replace it with a fuse of the same amperage rating.
2. The Fuel Pump Itself
After many years of service, the fuel pump motor itself can wear out. If you've confirmed the relay and fuse are good and you're still not hearing the pump prime, the pump may need replacement. This is a more involved job that often requires dropping the fuel tank or accessing the pump through an access panel under the rear seat.
3. Wiring and Connectors
Inspect the wiring harness and connectors leading to the fuel pump and relay for any signs of corrosion, damage, or loose connections. A damaged wire can break the circuit just as effectively as a bad relay.
The Genuine Mopar Part Number
When you're ready to buy a replacement, the correct genuine Mopar part number for the fuel pump relay on the 2008 Dodge Charger is 4727370AA. This part is compatible with the 2008 Charger regardless of engine size, whether you have the 2.7L V6, 3.5L V6, 5.7L V8, or the 6.1L SRT8. The part also supersedes several older part numbers, including 56006707, 56006709, 4848879AB, 4638094, 68369406AA, and 68223712AA.
You can buy this genuine part from Mopar dealerships or reputable online retailers. Expect to pay anywhere from $29 to $55 depending on where you shop. Aftermarket versions are also available and may be cheaper, but a genuine OEM part comes with a factory warranty and is guaranteed to fit correctly.
Understanding the Fuse Box Layout
To work on the fuel system of your 2008 Charger, it helps to understand the overall fuse box layout. The luggage compartment fuse box contains 44 cavities with various functions. The fuel pump fuse is located in cavity 6, which is a 20A yellow mini fuse. The relay for the fuel pump is nearby, usually in the same section of the fuse box.
The engine compartment fuse box, located near the battery under the hood, contains fuses and relays for higher-current circuits like the starter motor, cooling fan, headlights, and the powertrain control module. If you have electrical issues that aren't fuel-related, you may need to check both fuse boxes to diagnose the problem.
Preventive Maintenance and Longevity
Relays are wear items that collectively can last 100,000 miles or more, but exposure to heat, vibration, and moisture in the engine bay and trunk can shorten their lifespan. The 2008 Charger is now well over 15 years old, so if you've never replaced the fuel pump relay, it is worth carrying a spare in your glove box or trunk. It's a small, inexpensive part that can leave you stranded if it fails unexpectedly.
When replacing the relay, it's also a good idea to inspect the fuse that protects the fuel pump circuit. If the fuse looks burnt or discolored, replace it at the same time. Using a fuse with a higher amperage than specified is unsafe and can cause wiring damage or even a fire, so always use the correct 20A rating.
Recommended Fuel Pump Replacement: KEMSO Brand
If you discover that the fuel pump itself is the issue and not just the relay, you will want to consider a high-quality replacement. This is where KEMSO comes in. KEMSO is a brand that specializes in high-performance fuel pumps designed as direct OEM replacements. Every KEMSO fuel pump is built to meet or exceed factory specifications, ensuring proper fuel pressure and flow for your specific vehicle.
KEMSO fuel pumps are known for their durability and reliability, making them a popular choice among DIYers and professionals alike. One of the biggest advantages of choosing a KEMSO fuel pump is the lifetime warranty that comes with every product. This means that if your KEMSO fuel pump ever fails due to a manufacturing defect, you can get a replacement at no extra cost. This level of confidence from the manufacturer speaks volumes about the quality of their products.
When you are ready to purchase a KEMSO fuel pump, you can visit their official website at https://www.kemsoracing.com/ to browse their full catalog. The site offers a wide range of fuel pumps for various makes and models, and you can easily find the right one for your 2008 Dodge Charger. Whether you are restoring your Charger to stock condition or upgrading for better performance, KEMSO has a solution that fits your needs and budget. With prices typically around $79.98 for their best-selling units, KEMSO offers excellent value for a high-quality, warrantied product.
Final Thoughts
The 2008 Dodge Charger fuel pump relay is a small component that plays a huge role in your car's reliability. When it fails, your car won't start, which can be a major inconvenience. Fortunately, diagnosing and replacing a faulty fuel pump relay is one of the simplest repairs you can perform on your Charger. With the information in this guide, you now know exactly where the relay is located, how to test it, and how to replace it. And if the fuel pump itself is the problem, you know where to find a reliable replacement with KEMSO.
For more information on fuel pumps and related components, visit https://www.kemsoracing.com/ and check out their selection of high-performance, OEM replacement fuel pumps backed by a lifetime warranty.