2012 Dodge Charger Fuel Pump Wiring Diagram: A Practical Guide for Owners and DIY Mechanics

The bottom line up front: The 2012 Dodge Charger fuel pump wiring circuit follows a simple, predictable pattern—battery power flows through a fuse to the fuel pump relay, the relay sends power to the in-tank pump on the driver-side half of the saddle-style fuel tank, and the pump grounds through the chassis or the Powertrain Control Module (PCM). If your Charger cranks but will not start, or if you hear no prime hum from the tank when you turn the key to ON, the problem is almost always in one of three places: a blown fuse, a bad relay, or a failed pump. Understanding the wiring diagram before you start testing saves you time and prevents you from replacing parts you do not need.

This guide walks you through the exact wiring layout for the 2012 Charger, how to test each part of the circuit with a multimeter, how to read the relay schematic, and how to safely access and replace the pump. We also cover common mistakes and answer the questions that owners ask most often. Whether you are a seasoned mechanic or a first-time DIYer, this information gives you the confidence to diagnose the system correctly and fix it the first time.

Where the Fuel Pump Lives on a 2012 Charger

Before you touch any wires, you need to know where the pump is physically located. On the 2012 Dodge Charger, the fuel pump is inside the fuel tank, which sits under the rear of the vehicle behind the rear seat area. The tank is a saddle-style design, meaning it wraps around the driveshaft with two chambers connected by a crossover section. The fuel pump module is mounted in the driver-side half of the tank in most configurations.

You cannot see the pump from outside the car, and you will not find it under the hood. The pump is part of a sealed assembly called a "fuel pump module," which combines the pump, the fuel level sending unit, the strainer, and the pressure regulator in one unit. This is important because when you replace the pump, you replace the entire module, not just the pump motor.

How to confirm the pump location on your specific car:

  1. Check under the vehicle. With the car safely supported on jack stands, look above the rear axle on the driver side. You will see the plastic fuel tank shield and, behind it, the metal tank. The electrical connector and fuel lines route toward the driver-side of the tank on most 2011–2014 Charger models.

  2. Check for an access panel under the rear seat. Some early 2011 models built before a certain date have a round access plate under the rear seat cushion on the driver side. If you lift the rear seat bottom (pull up on the front edge and it pops free), look for a circular metal cover plate with three or four screws. If you see it, the pump is underneath. If you see only smooth floor pan, your car does not have the seat access design.

  3. Verify with your VIN. The safest way to confirm which configuration you own is to enter your VIN on the dealer's parts lookup system. The parts catalog will list the correct pump module and the correct installation procedure for your build date.

The Three Core Parts of the Fuel Pump Wiring Circuit

Every fuel pump wiring system on a modern vehicle has three core components, and the 2012 Charger is no exception. Once you understand these three elements, you can diagnose almost any fuel pump issue.

1. Power Source (Battery and Fuse)

The fuel pump draws 12 volts from the battery, usually through a dedicated fuse. The fuse protects the wiring and pump from overload. On the 2012 Charger, the fuel pump fuse is located in the underhood fuse box or the interior fuse panel. Typical fuse ratings for fuel pumps range from 15A to 30A, depending on the pump's current draw. Check the fuse first if the pump does not run.

2. Fuel Pump Relay

The relay acts as a switch. It uses a small electrical current from the ignition or PCM to control a large current to the pump. The relay has four pins on a standard Bosch-style relay:

  • Terminal 30 – Battery power input (connected directly to the battery positive through a fuse)
  • Terminal 87 – Output to the fuel pump (normally open, closes when the relay is energized)
  • Terminal 85 – One side of the relay coil (often receives a ground signal from the PCM)
  • Terminal 86 – The other side of the coil (usually connected to a 12-volt source from the ignition switch)

When you turn the key to ON, the PCM grounds pin 85, which closes the switch and sends power to the pump for a few seconds to prime the system. During cranking and running, the PCM keeps the relay closed.

3. Ground Path

The pump must have a solid ground connection. Many vehicles ground the pump through the chassis near the tank. Some modern cars use a ground signal sent by the PCM. A poor ground causes low voltage, weak fuel delivery, or no operation at all.

How to Read the Wiring Diagram for Your Charger

Wiring diagrams use standard conventions. Once you know what the symbols and colors mean, you can follow the circuit from the battery to the pump and back.

Wire colors you will likely see:

  • Black – Ground
  • Red or Yellow – Constant 12V battery power
  • Orange or Pink – Switched 12V (from ignition or relay)

Keep in mind that wire colors vary by manufacturer, so always confirm with the diagram specific to your vehicle.

Key symbols on the diagram:

  • Connector pin numbers are shown at each end of the wire. The diagram labels which pin goes to which component.
  • Splice or junction points are drawn as dots where wires join.
  • Ground symbols look like a downward triangle or three horizontal lines.

For older GM trucks, the fuel pump wire colors are dark green/white stripe (ground through PCM), gray (power from relay), and black (chassis ground). The 2012 Charger uses a similar logic, though the wire colors may differ. The important point is that the diagram shows you which pin on the pump connector carries power, which carries ground, and which carries the signal from the relay.

Step-by-Step: Diagnosing a Fuel Pump That Will Not Run

If your Charger cranks but will not start, or if you hear no prime hum from the tank, follow this sequence. Do not skip steps, and do not replace the pump until you have confirmed the problem is actually the pump.

Step 1: Check the Fuse

Locate the fuel pump fuse in the underhood or interior fuse box. Use a test light or multimeter to confirm power on both sides of the fuse. If the fuse is blown, replace it and try again. If it blows again, you have a short circuit to ground somewhere in the wiring.

Step 2: Test the Fuel Pump Relay

Find the relay, often labeled "FUEL PUMP" or "FP," and swap it with a known good relay of the same part number (like the horn or AC relay). If the pump runs after swapping, the relay was bad.

To test the relay directly, use a multimeter to check resistance between pins 85 and 86. You should see 50–120 ohms. Apply 12V to pin 86 and ground pin 85, and you should hear a click. If not, replace the relay.

Step 3: Listen for the Pump Prime

Turn the key to ON (without cranking). You should hear a 2–3 second whir from the fuel tank. If you hear nothing, the pump is not getting power or is dead.

Step 4: Test for Power and Ground at the Pump Connector

Raise the vehicle and locate the electrical connector at the fuel pump module. Use a multimeter to check for 12 volts at the power wire with the key ON. Check for continuity to ground on the ground wire. If you have power and ground but the pump does not run, the pump itself is faulty.

What the Fuel Pump Relay Schematic Tells You

Understanding the relay schematic is critical because a bad relay can mimic a failed pump or a bad PCM. The schematic shows two separate circuits: the control circuit (low current) and the power circuit (high current).

  • The control circuit includes the coil terminals (85 and 86). The PCM sends a ground signal on one side, and the other side receives 12 volts from the ignition circuit.
  • The power circuit includes terminals 30 and 87. Terminal 30 connects to battery positive through a fuse, and terminal 87 sends power to the pump when the relay closes.

Common symptoms of a failing fuel pump relay include:

  1. Engine cranks but does not start – This is the most obvious sign. When you turn the key, the engine cranks, but you do not hear the fuel pump prime for two seconds.
  2. Intermittent stalling – The relay may fail when hot or vibrate loose. The engine runs fine for a while, then suddenly dies without warning. After a few minutes, it restarts and runs again.
  3. No fuel pump prime sound – When you turn the key to ON, you should hear a faint whirring sound from the rear of the vehicle for about two seconds. If you hear nothing, the relay may not be closing.
  4. Fuel pump runs constantly – Less common, but if the relay sticks closed, the pump runs even with the key off. This drains the battery and can damage the pump or cause a fire hazard.
  5. Check Engine Light with fuel system codes – Codes like P0087 (fuel rail pressure too low) or P0230 (fuel pump primary circuit malfunction) indicate the PCM has detected a problem with the fuel delivery system.

Common Mistakes to Avoid When Working on the Wiring

Many DIYers make the same mistakes when diagnosing fuel pump wiring. Here is what to watch out for:

1. Skipping the fuse check. The fuse is the cheapest and easiest part to test. If you skip it and go straight to the pump, you may spend hundreds of dollars on a part you do not need.

2. Assuming the pump is bad when the relay is the culprit. A bad relay produces the exact same symptoms as a bad pump. Always test the relay before replacing the pump.

3. Ignoring the ground. A poor ground connection can cause low voltage, weak fuel delivery, or no operation. Check the ground path carefully.

4. Not relieving fuel pressure before disconnecting lines. Modern fuel injection systems maintain pressure up to 60–65 psi. If you disconnect a line without relieving pressure, fuel will spray out and create a fire hazard.

5. Not replacing the fuel filter. When you replace the fuel pump, replace the fuel filter at the same time. A clogged filter can cause a new pump to fail prematurely.

How to Access the Fuel Pump: Drop the Tank or Cut the Floor

There are two accepted ways to reach the fuel pump on a 2012 Charger, and each has pros and cons.

Method 1: Dropping the Fuel Tank (The Standard Shop Procedure)

This is what most professional shops do and what Chrysler's service manual recommends for most configurations. It involves the following steps:

  1. Disconnect the negative battery cable.
  2. Remove the fuel filler cap to relieve tank pressure.
  3. Raise the vehicle on a lift or support it securely with jack stands on all four corners.
  4. Remove the exhaust heat shields near the tank, which can sometimes require removing the rear section of the exhaust system entirely.
  5. Disconnect the fuel lines using the quick-connect tool.
  6. Disconnect the electrical connector for the fuel pump.
  7. Support the tank with a transmission jack or a purpose-built tank jack.
  8. Remove the two metal straps holding the tank in place.
  9. Lower the tank carefully, watching for the fuel fill hose and the vent hose.
  10. Remove the lock ring holding the pump module in place. A hammer and a brass punch or a special lock-ring tool work well here.
  11. Lift the pump module out, noting the orientation of the float arm before you remove it.

The entire job takes 3 to 5 hours for a DIY owner working carefully in a garage.

Method 2: Cutting an Access Hole in the Trunk Floor

This is a popular workaround for owners who do not want to deal with tank removal, especially on cars with heavily rusted straps. However, it must be done with care because you are modifying the structure of the car.

The trunk floor on the 2012 Charger does not come with a factory access panel in most trims. To access the pump from above, you cut a rectangular or round hole in the floor pan directly above the pump location. The key issue is that you must position the hole precisely, or you will not reach the pump.

Why Fuel Pumps Fail and How to Extend Pump Life

Fuel pumps typically last between 100,000 and 150,000 miles, but this varies based on driving habits and fuel quality. Here are the most common causes of failure:

1. Wear and Tear – Fuel pump internal parts degrade over time. Continuous operation under high temperatures and pressures gradually diminishes the pump's components.

2. Contaminated Fuel – Dirt, debris, and rust particles inside the fuel tank can obstruct the fuel pump, forcing it to work harder and ultimately leading to failure.

3. Running the Tank Low – Consistently running your Charger with less than a quarter tank of gas can shorten fuel pump life. The fuel inside the tank acts as a coolant for the pump, and running low means less cooling. Additionally, debris that settles at the bottom of the tank is more likely to be sucked into the pump when fuel levels are low.

4. Electrical Issues – Faulty electrical connections can lead to fuel pump failure. Damaged wiring, loose connections, or malfunctioning relays can disrupt power delivery.

Symptoms of a Failing Fuel Pump on Your Charger

If you are experiencing any of the following, the fuel pump may be failing:

  1. Engine sputtering or stalling – The pump may not be delivering a consistent flow of fuel to the engine.
  2. Difficulty starting the engine – A bad fuel pump can cause long cranking times or prevent the engine from starting altogether.
  3. Loss of power during acceleration – The pump cannot keep up with the engine's increased demand for fuel.
  4. Decreased fuel efficiency – When the pump cannot maintain proper pressure, the engine may run rich or lean, both of which reduce fuel economy.
  5. Whining noise from the fuel tank – A loud, high-pitched whining noise coming from the fuel tank area is often one of the first signs of a failing fuel pump.

Recommended Replacement: Choose KEMSO Fuel Pumps

When it is time to replace the fuel pump on your 2012 Dodge Charger, choosing a reliable brand matters. KEMSO offers high-performance fuel pumps that are designed as OEM replacements, meaning they match the fit, form, and function of the original part. Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your investment is protected.

KEMSO fuel pumps are built to deliver consistent fuel pressure and flow, ensuring your Charger runs smoothly under all driving conditions. Whether you drive a stock Charger or a modified build, KEMSO has a solution that meets your needs. Visit the KEMSO website at https://www.kemsoracing.com/ to browse their full line of fuel pumps and find the right one for your vehicle.

Final Thoughts

The 2012 Dodge Charger fuel pump wiring diagram is not complicated once you break it down into its three core parts: power, relay, and ground. When you have a no-start condition, work through the diagnostic steps in order—check the fuse, test the relay, listen for the prime, and then test for power and ground at the pump connector. Most of the time, the issue is a simple fuse or relay, not the pump itself.

If the pump is the problem, access it from under the vehicle by dropping the tank or, if your model allows, through an access panel. And when you are ready to replace it, choose a quality aftermarket option like KEMSO for reliable performance and lasting durability.

For more detailed information on fuel pump wiring, replacement procedures, and product options, visit https://www.kemsoracing.com/.


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