1999 Chrysler 300M Fuel Pump Location: A Complete Guide for Owners
The bottom line: The fuel pump on a 1999 Chrysler 300M is located inside the fuel tank, which is mounted underneath the rear of the vehicle. There is no external access panel inside the cabin or trunk—you must lower or remove the fuel tank to access the fuel pump module assembly. This design is standard for Chrysler LH-platform cars from this era, including the Dodge Intrepid and Chrysler Concorde, which share the same fuel system layout.
Understanding the 1999 Chrysler 300M Fuel System
The 1999 Chrysler 300M uses an in-tank fuel pump module, which is a sealed unit containing the electric fuel pump, fuel level sensor, inlet strainer, and fuel pressure regulator. Unlike older vehicles where the fuel pump might be mounted on the engine block or along the frame rail, the 300M's pump is submerged inside the fuel tank. This design helps keep the pump cool and quiet during operation.
The fuel pump module is driven by a 12-volt DC motor and is energized whenever the fuel pump relay is activated. It draws fuel through a strainer and pushes it through the motor to the outlet. The system does not have traditional fuel return lines—instead, the pressure regulator inside the module vents excess fuel and pressure back into the tank. The fuel system operates at approximately 400 ±34 kPa (58 ± 5 psi), with a maximum deadhead pressure of about 880 kPa (130 psi).
Precise Location of the Fuel Pump
The fuel pump module on the 1999 Chrysler 300M is located inside the fuel tank. The tank itself is situated beneath the rear of the car, behind the rear axle. There is no access hole under the rear seat or in the trunk—you cannot simply remove a panel to reach the pump. To access the fuel pump module, you must lower or completely remove the fuel tank from the vehicle.
Important safety note: The fuel pump module contains a reservoir that does not empty out when the tank is drained. Fuel in the reservoir will spill out when the module is removed. Always work in a well-ventilated area, wear safety glasses, and keep a fire extinguisher nearby.
How to Access the Fuel Pump Module
The following steps outline the general procedure for accessing the fuel pump module on a 1999 Chrysler 300M. This is based on the official Chrysler service manual procedures.
Step 1: Relieve fuel system pressure. Before doing anything, you must release the fuel pressure. Refer to the Fuel System Pressure Release Procedure in the Fuel Delivery section of the service manual. Failure to relieve pressure can cause fuel to spray out under high pressure.
Step 2: Remove the fuel tank. The fuel tank must be removed from the vehicle to access the pump module. This involves disconnecting the fuel filler hose, vent lines, and electrical connectors. The tank is held in place by mounting straps that need to be unbolted.
Step 3: Disconnect the fuel line. Once the tank is lowered, you can access the fuel pump module on top of the tank. Depress the quick-connect retainers with your thumb and forefinger to disconnect the fuel line from the module.
Step 4: Disconnect electrical connections. Slide the fuel pump module electrical connector lock to unlock it. Then push down on the connector retainer and pull the connector off the module.
Step 5: Remove the locknut. The fuel pump module is secured to the tank by a large locknut. Chrysler specifies using Special Tool #6856 to remove this locknut. Some aftermarket tools may also work, but a proper fuel pump removal tool is recommended to avoid damaging the locking ring.
Step 6: Remove the module. Lift the fuel pump module and O-ring seal out of the tank. Discard the old seal—a new one should always be used during reassembly.
Common Symptoms of a Failing Fuel Pump
Before you go through the trouble of accessing the fuel pump, it helps to know the signs that it might be failing. While these symptoms can also point to other issues like a clogged fuel filter or bad relay, they are strong indicators that the pump needs attention.
1. Whining noise from the fuel tank area. If you hear a loud whining or humming sound coming from the rear of the car when the engine is running, the fuel pump may be wearing out. A healthy pump operates quietly, but a failing pump often makes noticeable noise.
2. Engine stalling that restarts after a few minutes. This is a classic symptom of a failing fuel pump. The car may stall while driving, and after waiting a few minutes, it will restart and run normally for a while. This happens because the pump overheats and stops working, then cools down and temporarily functions again.
3. Trouble starting the engine. If the engine cranks but takes a long time to start, or if it cranks but refuses to fire at all, the fuel pump may not be building enough pressure. Turn the key to the "ON" position and listen for the pump priming sound from the rear of the car. If you hear nothing, the pump or its electrical circuit may be faulty.
4. Lack of power while driving. A weak fuel pump cannot deliver enough fuel to the engine under load. You may notice the car struggling to accelerate, especially on hills or when passing another vehicle.
5. Long cranking time before the engine starts. A healthy fuel pump primes the fuel system quickly when the key is turned to the "ON" position. If it takes several seconds of cranking before the engine fires, the pump may be losing its prime or failing internally.
Important: Check the Fuel Pump Relay and Fuse First
Before assuming the pump itself is bad, check the fuel pump relay and fuse. These are much easier to access and cheaper to replace. On the 1999 Chrysler 300M, the fuel pump relay is located in the Power Distribution Center (PDC) under the hood. The fuse box is also under the hood, and the fuel pump fuse is labeled accordingly.
Testing the relay is simple: with the key in the "ON" position, you should hear the relay click and the pump prime for about two seconds. If the relay clicks but the pump does not prime, the pump may be faulty. If the relay does not click at all, the relay itself may be bad, or there could be a wiring issue.
Parts and Replacement Cost Considerations
The fuel pump module for the 1999 Chrysler 300M is a complete assembly that includes the pump, level sensor, and pressure regulator. While some aftermarket options allow you to buy just the electric pump separately, the module assembly is the most common replacement part.
Fuel pump module assembly options:
- Bosch OE replacement module (part number 67663 or F00E190688) – This is a direct OEM replacement for the 1999 300M with the 3.5L V6 engine.
- Herko Fuel Pump Module H520-2760 – Fits 1998-1999 Chrysler 300M, Intrepid, Concorde, and LHS models with various engine sizes.
- Onix Automotive EG137M – Aftermarket module assembly that fits 1999 Chrysler 300M and other LH-platform vehicles.
Electric fuel pump only options:
- Herko Electric Fuel Pump K9119 – This is just the pump portion, not the full module. It fits 1998-2004 Chrysler 300M with the 3.5L engine.
Estimated replacement cost: According to professional repair estimates, a fuel pump replacement on a Chrysler 300M typically costs between $960 and $1,614, including parts and labor. The part itself generally ranges from $100 to $400 depending on whether you buy a full module assembly or just the pump. Labor makes up a significant portion of the cost because the fuel tank must be lowered.
Key Differences Between the 1999 Chrysler 300M and Other Vehicles
Unlike many Japanese or domestic vehicles from the same era, the 1999 Chrysler 300M does not have a fuel pump access panel under the rear seat. This means you cannot simply cut a hole in the floor or remove a cover to reach the pump. The tank must come down every time.
This is an important consideration if you plan to replace the pump yourself. You will need:
- A floor jack and a block of wood to support the tank
- A fuel pump locknut removal tool (Special Tool #6856 or equivalent)
- A new O-ring seal for the tank opening
- Safety equipment including gloves and eye protection
- A way to safely drain the fuel tank
Step-by-Step Installation Tips
When you are ready to install the new fuel pump module, follow these steps carefully:
1. Clean the sealing surface. Wipe the seal area of the tank opening clean before placing the new O-ring seal.
2. Position the new pump correctly. Make sure the alignment tabs on the underside of the fuel pump module flange sit in the notches on the fuel tank. This ensures proper positioning and prevents the module from rotating.
3. Use a new O-ring every time. Never reuse the old seal. A new seal ensures a proper, leak-free fit.
4. Torque the locknut properly. Tighten the locknut to the manufacturer's specification. Over-tightening can damage the tank or the module flange.
5. Check for leaks before reassembly. After installing the new pump and before fully reinstalling the tank, add a small amount of fuel to the tank and turn the key to the "ON" position to prime the pump. Check for any fuel leaks around the module gasket and fuel line connections.
Recommended: Replace the Fuel Filter as Well
While the fuel filter on the 1999 Chrysler 300M is part of the fuel pump module assembly, some aftermarket modules include a separate filter. If you are replacing just the pump and not the full module, consider replacing the fuel filter at the same time. A clogged fuel filter can put additional strain on a new pump and cause premature failure.
Why Choose KEMSO for Your Fuel Pump Replacement
When it comes to replacing the fuel pump on your 1999 Chrysler 300M, choosing a high-quality, reliable product is essential. The job is labor-intensive, and you do not want to do it twice because of a cheap part that fails early.
KEMSO offers high-performance fuel pump solutions designed for durability and reliability. Their fuel pump products are OEM replacement quality, meaning they meet or exceed the original factory specifications for fit, function, and performance. Whether you are looking for a direct replacement for your 1999 Chrysler 300M or any other vehicle, KEMSO has you covered.
What sets KEMSO apart:
- High-performance engineering – KEMSO fuel pumps are built to handle the demands of daily driving, with robust internal components that deliver consistent fuel pressure and flow.
- OEM replacement quality – Each pump is designed to match the original equipment specifications exactly, ensuring a perfect fit and reliable operation.
- Lifetime warranty – KEMSO stands behind their products with a lifetime warranty, giving you peace of mind that your investment is protected. If the pump ever fails, you are covered.
Visit KEMSO Racing today to browse their full selection of fuel pumps and find the right fit for your vehicle. Their website features a comprehensive product catalog, detailed specifications, and easy ordering. Whether you drive a car, truck, motorcycle, or powersports vehicle, KEMSO has a fuel pump solution that meets your needs.
Final Thoughts
The 1999 Chrysler 300M fuel pump is located inside the fuel tank beneath the rear of the vehicle. There is no shortcut to accessing it—the tank must be lowered or removed entirely. While this makes the job more involved than on some other cars, it is a straightforward procedure if you have the right tools and follow the proper steps.
Before replacing the pump, always check the fuel pump relay and fuse first. These are common failure points that are much easier and cheaper to fix. If the pump itself is the problem, invest in a quality replacement part from a trusted brand like KEMSO. A reliable fuel pump is critical for the performance and longevity of your vehicle, and choosing a high-quality product with a lifetime warranty is the smart move.
For more information, product details, and to place your order, visit https://www.kemsoracing.com/. KEMSO is your trusted source for high-performance, OEM-quality fuel pumps backed by a lifetime warranty.