2021 Ford Mustang Radiator Fan Isn't Working

Diagnosing the Causes of a Non-Functioning Radiator Fan in Your 2021 Ford Mustang and How to Fix It

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Reviewed by
Aisha
Written by RepairPal Car Genius
Updated January 14, 2025
0%
34% chance it's the
Fan Motor or Clutch
0%
28% chance it's the
Fan Relay or Fuse
0%
23% chance it's the
Temp Sensor or Fan Control Module
0%
15% chance it's
Something else
The most common reasons a 2021 Ford Mustang radiator fan isn't working are the fan assembly, the fan clutch, or the coolant temperature sensor.
  • Fan Motor or Clutch: A faulty fan motor or a malfunctioning fan clutch can result in inadequate cooling, causing the engine to overheat.
  • Fan Relay or Fuse: A faulty fan relay or blown fuse can prevent the cooling fan from operating, leading to engine overheating.
  • Temp Sensor or Fan Control Module: A faulty temperature sensor or fan control module can result in incorrect readings, causing the engine to overheat or the cooling fan to operate improperly.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2021 Ford Mustang radiator fan isn't working?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Over time serpentine belts stretch, crack, and the ribs that ride on the accessory pulleys being to wear smooth. A squealing noise that increases with engine speed or as engine driven accessories are turned on may be noted. The noise is caused by the belt slipping on the pulleys, insufficiently driving them. Ineffective air conditioning, a battery warning light, or intermittent power steering assist can result from this.

»MORE: Symptoms of a bad serpentine belt

The bad thermostat can cause two different sets of problems, depending on whether it's stuck open or stuck closed.

A thermostat that is stuck open can cause the engine to run colder than normal and turn on the check engine light. It may also cause poor fuel mileage and the heater to blow cool air.

A thermostat that is stuck closed will cause the vehicle to overheat. If a new thermostat doesn't resolve engine temperature problems, the cooling system needs to be checked for other issues.

» LEARN MORE: Signs of a bad thermostat, and how to fix it

When the radiator fans stop functioning properly, the engine temperature will rise. The spike in temperature will be highest when the vehicle is idling at a stop, but should subside once the vehicle begins moving again.

Additionally, the air conditioner typically won't blow as cold. This is because the air from the radiator fans also blows across the air conditioning condenser, so when the fans fail, both systems suffer.

You'll also usually see the check engine light and notice a drop in fuel economy. It's possible the fan will start making noise if it's failing, as well.

What are the steps to diagnose the non-functioning radiator fan in a 2021 Ford Mustang?

To effectively diagnose a non-functioning radiator fan in a 2021 Ford Mustang, it's essential to adopt a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by inspecting the fuse associated with the radiator fan; a blown fuse is a common and easily rectifiable issue that can halt fan operation. If the fuse is intact, proceed to examine the relay that controls the fan, as a malfunctioning relay can also prevent the fan from activating. Next, test the fan motor directly by applying power to it; if it fails to operate, the motor may need replacement. Additionally, check the temperature sensor, which is vital for triggering the fan when the engine reaches a certain temperature. Look for any wiring issues, such as damaged or loose connections, that could disrupt the fan's functionality. Finally, utilize a diagnostic tool to scan for any trouble codes that may provide insight into the underlying problem. By following this structured diagnostic approach, you can efficiently identify and resolve the issue with your radiator fan.

What are the common problems that could cause the radiator fan to stop working in a 2021 Ford Mustang?

When diagnosing why the radiator fan in a 2021 Ford Mustang has stopped working, it's crucial to consider several common issues that could be at play. A faulty fan motor is often the primary suspect, as it can fail to spin, leading to overheating. Additionally, a blown fuse in the fan circuit can interrupt the power supply, effectively shutting down the fan. Another potential culprit is a defective relay, which is responsible for sending the electrical signal to the fan; if this component fails, the fan won't operate. Physical damage to the fan blades can also hinder performance, preventing adequate air circulation. Furthermore, if the coolant temperature sensor is malfunctioning, it may not trigger the fan to activate at the appropriate temperature, exacerbating overheating problems. Lastly, wiring issues, such as corrosion or damage, can disrupt the electrical flow to the fan, causing it to fail. Addressing these issues promptly is essential to maintain optimal engine temperature and prevent further damage to your vehicle. Regular inspections and maintenance can help catch these problems early, ensuring your Mustang runs smoothly.

How urgent is it to repair the non-functioning radiator fan in a 2021 Ford Mustang to prevent engine overheating?

Repairing a non-functioning radiator fan in your 2021 Ford Mustang is not just a matter of convenience; it is a critical safety concern that demands immediate attention. The radiator fan is essential for regulating the engine's temperature, and when it fails, the risk of engine overheating escalates dramatically. Overheating can lead to severe damage, including warped cylinder heads or a blown head gasket, which can result in costly repairs that far exceed the expense of a simple fan replacement. Moreover, an overheating engine can leave you stranded, creating a hazardous situation on the road. Therefore, addressing the malfunctioning radiator fan promptly is crucial to ensure your vehicle operates safely and efficiently, preventing both financial strain and potential safety hazards. Ignoring this issue could lead to dire consequences, making it imperative to act swiftly.

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