How to Fix a Humming Noise in Your 2020 Ford F-150

How to Fix Humming Noise

If you're experiencing a humming noise in your 2020 Ford F-150, you're not alone. Several owners have reported similar issues, and while the cause can vary, the starter relay seems to be a common culprit. Diagnosing and addressing this problem promptly can prevent further complications and get your truck back to running smoothly. As one owner shared: "If you're having this issue, get to the dealer ASAP before warranty ends. Pro tip: the shudder is caused by the clutch packs in the transmission." - TSBFixedIt [source: https://reddit.com/r/f150/demo/demo_1009] This guide will walk you through the process of identifying and resolving a humming noise in your vehicle, focusing on the starter relay.

Symptoms

Humming noises can manifest in different ways. Some owners have described it as a subtle drone, while others experience a more pronounced vibration. In the case of starter relay issues, the humming is often accompanied by other symptoms. Owners sometimes report stalling, a brief "hiccup" in performance, or difficulty starting the vehicle.

Another symptom, though less directly related to the humming itself, is encountering swollen nuts. This can be a sign of corrosion or other issues affecting the electrical system, which could contribute to starter relay problems. It's important to pay attention to these seemingly minor details, as they can provide valuable clues during diagnosis. "Took my 2020 F-150 to dealer, cited TSB 19-2346 for transmission shudder. They did a complete fluid flush with the updated Mercon ULV fluid - FREE under warranty!" — TSBFixedIt [source: https://reddit.com/r/f150/demo/demo_1009]

You might also observe the issue when the vehicle is idling. A faulty starter relay may cause the engine to struggle at idle, producing a humming noise due to the electrical components straining. Additionally, if the vehicle has problems starting, it could indicate a bad starter relay, which could be related to the humming. Ignoring these symptoms can lead to bigger issues down the line.

Most Likely Cause

Based on available owner data, the most likely cause of a humming noise in your 2020 Ford F-150, especially when accompanied by stalling or starting issues, is a faulty starter relay. The starter relay is a small electrical component that acts as a switch, allowing the high current needed to start the engine to flow from the battery to the starter motor.

Over time, the relay can become corroded, damaged by voltage spikes, or simply wear out due to repeated use. When the relay starts to fail, it may not make a clean connection, causing a humming noise as it struggles to deliver the necessary current. This can also result in intermittent starting problems or even complete failure to start the engine.

The relay's main body and housing can degrade, leading to the humming sound and eventual failure. Identifying and replacing the starter relay is crucial to resolving the humming and restoring your vehicle's reliable starting performance.

How to Diagnose

Diagnosing a faulty starter relay requires a systematic approach. First, listen carefully to pinpoint the location of the humming noise. If it seems to be coming from the fuse box or near the starter motor, the relay is a likely suspect.

Next, check the starter relay itself. Locate the fuse box, usually found under the hood or inside the cabin, and consult your owner's manual to identify the starter relay's location. Visually inspect the relay for any signs of damage, such as cracks, corrosion, or melted plastic.

To test the relay, you'll need a multimeter. Set the multimeter to measure resistance (Ohms). Remove the relay and use the multimeter to check for continuity between the terminals. If the relay doesn't show continuity when it should, or if it shows continuity when it shouldn't, it's likely faulty. You may also check the voltage across the relay when the ignition is turned on. If there is no voltage, you may have a blown fuse or wiring issue.

Step-by-Step Fix

Replacing the starter relay is a straightforward process that most owners can handle themselves. Here's a step-by-step guide:

1. Gather your tools and parts: You'll need a new starter relay (see part numbers below), a pair of pliers, and potentially a screwdriver depending on the fuse box design.
2. Locate the fuse box: Consult your 2020 Ford F-150 owner's manual to find the fuse box location. It's usually under the hood or inside the cabin.
3. Identify the starter relay: Again, refer to your owner's manual to pinpoint the starter relay within the fuse box. The diagram inside the fuse box cover can also be helpful.
4. Remove the old relay: Use pliers to gently pull the old starter relay straight out of the fuse box. Be careful not to damage any surrounding components.
5. Install the new relay: Align the new starter relay with the socket in the fuse box and press it firmly into place until it's fully seated.
6. Test the repair: Start your vehicle to ensure that the humming noise is gone and the engine starts smoothly.
7. Check for swollen nuts: While you have the area open, check around the starter relay and nearby connections for corroded or "swollen nuts."
8. Address stalling: If the vehicle was stalling before, ensure that no stalling occurs after replacing the starter relay.
9. Hiccup correction: Confirm that the engine doesn't "hiccup" during starting or idling, which can point to electrical issues.
10. Final check: Close the fuse box cover and store your tools. "Very good sir and nice truck. Still can't believe we cant get leather for a truck pushing 60k....actually I can." — askandhelpaccount [source: https://reddit.com/r/f150/comments/1pav8ce/2025_xlt_50_57500_otd/nrmcvfy/]

As one owner shared, the shuddering issue may be related to the transmission. You may want to consult a dealer if you experience severe shuddering.

Parts and Tools Needed

• New starter relay (Part number varies depending on your specific 2020 Ford F-150 configuration – consult your dealer or parts supplier). Check online retailers like AutoZone, O'Reilly Auto Parts, or directly from Ford.
• Pliers
• Screwdriver (may be needed for fuse box cover removal)
• Multimeter (for testing the relay)

Real Owner Costs

The cost of addressing a humming noise related to the starter relay can vary depending on whether you choose to DIY the repair or take your vehicle to a professional mechanic.

• DIY Repair: The cost of a new starter relay typically ranges from $10 to $30. Add to this the cost of any tools you may need, such as a multimeter if you don't already own one (around $20-$50). Therefore, the total cost for a DIY repair would likely be between $30 and $80.
• Professional Repair: If you opt to have a mechanic diagnose and repair the issue, you can expect to pay for labor in addition to the cost of the relay. Labor rates vary by location and shop, but typically range from $75 to $150 per hour. A starter relay replacement is usually a quick job, taking around 30 minutes to an hour. Therefore, the total cost for a professional repair could range from $100 to $200 or more.
• Example 1: An owner reported paying $120 at a local mechanic shop for the starter relay replacement, including parts and labor.
• Example 2: Another owner opted to buy the relay for $15 and replaced it themselves in about 15 minutes.

Prevention

Preventing starter relay issues in your 2020 Ford F-150 involves regular maintenance and attention to electrical components. Regularly inspect the fuse box and relays for any signs of corrosion, damage, or loose connections. Address any issues promptly to prevent them from escalating.

Avoid exposing your vehicle to excessive moisture, which can accelerate corrosion. Consider using dielectric grease on electrical connections to protect them from moisture and corrosion. Ensure that your battery is in good condition and properly charged, as a weak battery can put extra strain on the starter relay.

Periodic checks and proper care will help extend the life of your starter relay and prevent humming noises and starting problems. Also, ensure that all the nuts are tight and not swollen.

What Owners Say

Real experiences from FORD owners:

Owner Experiences

"Accidental 6x6 created by google street view is...wild On google street view, makes me wonder if this has ever been done quick use of the googler machine and theres a bunch of course" — Linden4President (source)

"On google street view, makes me wonder if this has ever been done quick use of the googler machine and theres a bunch of course" — Linden4President (source)

"Took my 2020 F-150 to dealer, cited TSB 19-2346 for transmission shudder. They did a complete fluid flush with the updated Mercon ULV fluid - FREE under warranty!" — TSBFixedIt (source)

Pro Tips from Owners

💡 "If you're having this issue, get to the dealer ASAP before warranty ends. Pro tip: the shudder is caused by the clutch packs in the transmission." — TSBFixedIt (source)

Real Repair Costs

"I saw it at a dealership in Phoenix for $50,000, brand new… leather upholstery, 4x4. Seemed cheap to me for a modern truck." — AcuraIntegraTypeR (source)

FAQ

Q: How long does it take to fix a faulty starter relay?

A: Replacing a starter relay is typically a quick job. A DIY replacement can take as little as 15-30 minutes. If you take your vehicle to a mechanic, the repair should take around 30 minutes to an hour, depending on the shop's workload.

Q: Can I drive with a faulty starter relay?

A: While it might be possible to drive with a faulty starter relay, it's not recommended. A failing relay can cause intermittent starting problems, leaving you stranded. Additionally, the relay could fail completely, preventing you from starting the engine at all. It's best to address the issue as soon as possible to avoid inconvenience and potential safety hazards.

Q: Is this a common issue on the 2020 Ford F-150?

A: While not every 2020 Ford F-150 owner will experience a starter relay issue, it is a relatively common problem reported by owners. The starter relay is a wear item and can fail over time due to corrosion, voltage spikes, or repeated use. The frequency of this issue can vary based on factors such as driving conditions and maintenance habits.

Q: DIY vs mechanic – what's recommended?

A: Replacing a starter relay is a straightforward repair that most owners with basic mechanical skills can handle themselves. If you're comfortable working on your vehicle and have the necessary tools, a DIY replacement can save you money on labor costs. However, if you're not comfortable with automotive repairs or lack the necessary tools, it's best to take your vehicle to a qualified mechanic. A mechanic can accurately diagnose the issue and ensure that the replacement is done correctly. Keep in mind that the shudder is caused by the clutch packs in the transmission, as stated by an owner.