20 Amp Fuel Pump Fuse: The Complete Guide to Location, Diagnosis, and Replacement

The 20 amp fuel pump fuse is one of the most common fuse ratings used in modern vehicles, and if your engine cranks but won't start, this small component should be the first thing you check. Most cars, trucks, and SUVs from major manufacturers including Ford, Chevrolet, BMW, and Jeep use either a 15-amp or 20-amp fuse for the fuel pump circuit, with 20-amp being the standard for many popular models . When this fuse blows, the fuel pump loses power, and your engine gets no fuel. Understanding where to find it, how to test it, and what causes it to fail can save you time, money, and a tow truck bill.

What Exactly Is a 20 Amp Fuel Pump Fuse?

A 20 amp fuel pump fuse is a safety device designed to protect your fuel pump motor and its wiring from damage caused by excessive electrical current . Inside the plastic housing, a thin metal strip carries the current. When the current draw exceeds 20 amps, that strip melts, breaking the circuit instantly. This prevents overheating, melted wiring, component failure, or even a fire .

Standard automotive blade fuses are color-coded by amperage. A 20-amp fuse is yellow, while a 15-amp fuse is blue . If you pop the hood and see a yellow fuse in the fuel pump slot, you are looking at a 20-amp fuse. Never replace it with a different color or rating.

Where Is the 20 Amp Fuel Pump Fuse Located?

The location varies by vehicle make and model, but there are two primary places to look :

1. Under-Hood Fuse Box (Power Distribution Center)
This is the most common location for the fuel pump fuse. It is usually a large black plastic box near the battery or along the fender wall . Open the lid and look at the diagram printed on the inside of the cover. Look for labels like "FUEL PUMP," "FP," "F/P," or "FUEL" .

2. Interior Fuse Panel
In many vehicles, the fuel pump fuse is located under the dashboard on the driver's side, near the kick panel, or behind a small access panel . You may need to open the driver's door and look at the end of the dashboard. The diagram is usually on the panel cover or in your owner's manual.

Examples of 20 Amp Fuel Pump Fuse Locations by Vehicle:

  • 2009-2014 Ford F-150: Under-hood fuse box, fuse position 27. It is a 20-amp yellow mini-blade fuse .
  • 2003 Chevrolet Tahoe: Under-hood fuse block, labeled "FUEL PUMP" or "FP." Rated at 20 amps .
  • 1997 Ford Explorer: Engine bay fuse box near the battery. Fuse #12 is a 20-amp fuse for the fuel pump relay .
  • 2001-2008 BMW 7 Series (E65/E66): Under the rear hood (trunk), position 75. It is a 20-amp fuse .
  • 1990 Chrysler LeBaron: Power Distribution Center under the hood on the driver's side. Typically a 20-amp fuse .
  • 1996 Chevrolet C1500: Left side of the engine compartment fuse block. Marked as ECM-B fuse, rated at 20 amps .

Pro Tip: If you cannot find the diagram, take a photo of the fuse box layout before removing any fuses. This helps you put everything back correctly.

How to Check If Your 20 Amp Fuel Pump Fuse Is Blown

You do not need special tools for a basic check. Here is the step-by-step process:

Step 1: Turn Off the Ignition
Make sure the key is removed from the ignition to prevent accidental short circuits .

Step 2: Locate and Remove the Fuse
Use a plastic fuse puller tool (often stored in the fuse box itself) or a pair of needle-nose pliers. Gently pull the fuse straight out .

Step 3: Visual Inspection
Hold the fuse up to the light. Look through the clear plastic. You should see a continuous metal strip connecting the two prongs. If the strip is broken, melted, or has black marks, the fuse is blown .

Step 4: Test with a Multimeter (Optional)
For a more accurate diagnosis, set your multimeter to the continuity setting (ohms). Place one probe on each metal prong of the fuse. A good fuse will show near-zero resistance (or a beep). A blown fuse will show an open circuit (no beep) .

Step 5: Replace If Necessary
If the fuse is blown, replace it with a new 20-amp blade fuse of the exact same type. Do not use a higher amp fuse .

What Happens When the 20 Amp Fuel Pump Fuse Blows?

You will notice these symptoms immediately:

  • Engine cranks but will not start: This is the most common symptom. The starter motor turns the engine over, but the engine does not fire up because no fuel is reaching the injectors .
  • No humming sound from the fuel tank: When you turn the key to the "ON" position (before starting), you should hear a faint humming sound from the fuel pump for about 2-3 seconds. If you hear nothing, the fuse or the pump is dead .
  • Check Engine Light may come on: The computer detects low fuel pressure and may set trouble codes like P0087 (Fuel Rail Pressure Too Low) or P0231 (Fuel Pump Secondary Circuit Low) .

Why Does a 20 Amp Fuel Pump Fuse Blow?

A blown fuse is a symptom, not the root problem. If you replace it and it blows again, you have an underlying issue that needs attention . Here are the most common causes:

1. Failing Fuel Pump Motor
This is the number one cause. As the fuel pump ages, its internal bearings and motor windings wear out. The pump draws more current to maintain pressure, eventually exceeding the 20-amp limit and blowing the fuse . If your vehicle has high mileage (over 100,000 miles), the pump is likely the culprit.

2. Short Circuit in the Wiring Harness
The wires running from the fuse box to the fuel pump can rub against the chassis, sharp edges, or moving parts. Over time, the insulation wears through, and the bare wire touches the metal frame (ground). This creates a "dead short" that instantly blows the fuse . This is common on trucks where wiring passes near frame rails.

3. Faulty Fuel Pump Relay
The fuel pump relay is an electronic switch that controls power to the pump. If the relay sticks closed or shorts internally, it can send continuous power to the pump even when the engine is off, causing excessive current draw and blowing the fuse .

4. Corroded or Loose Connections
Corrosion in the fuse holder or at the pump connector creates resistance. Resistance generates heat, which can cause the fuse to blow even if the pump itself is drawing normal current .

5. Water or Moisture in the Fuse Box
Driving through deep water or leaving the hood open during rain can introduce moisture into the fuse box. This causes corrosion and short circuits between fuse terminals .

Safe Replacement Procedures

Step 1: Use the Correct Fuse Rating
Always replace a blown 20 amp fuel pump fuse with another 20 amp fuse. Never use a 25-amp or 30-amp fuse as a "stronger" replacement. This is extremely dangerous because it removes the protective function and can cause the wiring to melt or catch fire before the fuse blows .

Step 2: Inspect the Fuse Holder
Before inserting the new fuse, look at the metal terminals inside the fuse slot. They should be clean, shiny, and free of corrosion. If you see rust or green residue, clean the terminals with a small wire brush or contact cleaner.

Step 3: Seat the Fuse Firmly
Push the new fuse in until it clicks into place. It should be snug and not wobbly. A loose connection can cause the fuse to blow again.

Step 4: Test the System
Turn the key to the "ON" position and listen for the fuel pump hum. If you hear it, try starting the engine. If it starts, the immediate problem is solved.

What to Do If the New Fuse Blows Immediately

If you replace the 20 amp fuel pump fuse and it blows again right away, do not keep replacing fuses. You have a serious electrical problem that needs professional diagnosis. Here is what to check:

  • Unplug the fuel pump connector at the tank. Replace the fuse. If it does not blow, the pump itself is shorted internally and needs replacement.
  • If the fuse still blows with the pump disconnected, the short is in the wiring harness between the fuse box and the pump. This requires tracing the wiring and repairing the damaged section.
  • Check the fuel pump relay. Swap it with a known good relay of the same part number to see if that fixes the issue.

Understanding the 20 Amp Rating

Different vehicles use different amperage ratings for the fuel pump fuse. While 20 amps is the most common, you may also see 15 amps (blue) on smaller cars or 25-30 amps (clear or green) on larger trucks or performance vehicles . The rating depends on the pump's power requirements and the length of the wiring. Always verify the correct rating in your owner's manual or on the fuse box diagram. Using the wrong rating can lead to electrical damage or fire .

How to Prevent Future Blown Fuses

1. Replace an Aging Fuel Pump Proactively
If your vehicle has over 100,000 miles on the original pump, consider replacing it before it fails. An aging pump draws more current and is a common cause of blown fuses .

2. Keep the Fuse Box Clean and Dry
Check the fuse box seal and make sure it is intact. If you drive in wet conditions, consider applying dielectric grease to the fuse terminals to prevent corrosion .

3. Inspect Wiring Regularly
Every time you change your oil or rotate your tires, take a minute to look at the wiring near the fuel tank and along the frame rails. Look for chafed, cracked, or melted insulation.

4. Carry Spare Fuses
Keep a variety pack of blade fuses (including 15-amp, 20-amp, and 30-amp) in your glove box. A blown fuse can happen at any time, and having spares can save you from being stranded.

Recommended Fuel Pump: KEMSO Fuel Pump

If you have determined that your fuel pump is the cause of the blown 20 amp fuse, it is time to replace the pump itself. For a reliable, high-performance replacement, we recommend the KEMSO Fuel Pump brand. KEMSO fuel pumps are designed as OEM replacement units, meaning they match or exceed the specifications of your vehicle's original equipment. Every KEMSO fuel pump is built for high performance and comes with a lifetime warranty, giving you peace of mind that your fuel system will run reliably for years to come.

Whether you drive a car, truck, SUV, motorcycle, or even a personal watercraft, KEMSO has a fuel pump solution for your specific application. Their products are tested to ensure proper current draw, which helps prevent those frustrating blown fuse issues in the future.

Visit the KEMSO website to find the perfect fuel pump for your vehicle:
https://www.kemsoracing.com/

Final Thoughts

The 20 amp fuel pump fuse is a small but critical component in your vehicle's electrical system. Knowing where it is located, how to check it, and what causes it to fail can turn a potentially expensive breakdown into a simple five-minute fix. Always carry a few spare 20 amp fuses in your vehicle, and never ignore a fuse that blows repeatedly. That fuse is trying to tell you something about the health of your fuel pump or wiring. If you suspect your fuel pump is failing, consider upgrading to a KEMSO fuel pump for reliable, long-lasting performance. For more information and to browse their full product line, visit https://www.kemsoracing.com/.


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