Dodge Ram 3500 Radiator Fan Isn't Working

Diagnosing the Causes of a Non-Functioning Radiator Fan in Your Dodge Ram 3500 and How to Fix It

Find Repair Location
Reviewed by
Devin Cabugcal
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 Dodge Ram 3500 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 Dodge Ram 3500 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 first indication of a defective fan clutch is a healthy cooling system that runs below or above the normal temperature range. This is due to the fan running too fast or too slow. Also, a seized cooling fan will cause a loud roaring fan noise from under the hood every time the accelerator is pressed, and the engine will feel as if it lacks power. In this situation it would be very difficult to turn the engine cooling fan by hand, of course when the vehicle is off. Finally, if the clutch fails the fan will either turn very slowly, and not respond well to engine speed.

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 engine coolant temperature sensor fails, it will send inaccurate information to the vehicle’s computer, causing the computer to react to false operating conditions. This will cause the engine to consume more fuel than normal, depleting fuel mileage, and causing black, sooty smoke from the engine under moderate to heavy acceleration. The check engine light will illuminate, and on-board diagnostic trouble codes may be stored for exhaust and emission system failure, fuel delivery system failure, and engine cooling system failure. Overheating may also occur, as the coolant sensor may be leaking fluid out of the engine, creating a an air pocket in the system.

Troubleshooting Radiator Fan Issues in a Dodge Ram 3500

When troubleshooting radiator fan issues in your Dodge Ram 3500, begin with the most straightforward solutions to save time and effort. Start by checking the fuse associated with the radiator fan; a blown fuse is a common culprit that can easily be replaced. Next, inspect the wiring for any signs of damage or disconnection, as faulty wiring can disrupt the fan's operation. If the fan remains unresponsive, examine the fan itself to ensure it is functioning properly. Pay attention to the fan clutch, especially if your model uses an oil-filled type, as this component can affect the fan's performance and may require servicing. Additionally, consider the role of the Powertrain Control Module (PCM), which regulates the fan's operation; any discrepancies in its control signals can lead to malfunction. Lastly, be aware that inadequate fan operation can contribute to transmission overheating, particularly during towing. By systematically addressing these areas, you can effectively diagnose and resolve radiator fan issues, ensuring your vehicle runs smoothly.

What Are the Common Causes of a Non-Working Radiator Fan in a Dodge Ram 3500?

When troubleshooting a non-working radiator fan in a Dodge Ram 3500, it's essential to understand the common problems that could be causing the issue. One of the first areas to check is the fan assembly itself, as a faulty unit can prevent the fan from operating correctly. Additionally, the fan clutch plays a crucial role in regulating the fan's operation; if it malfunctions, the fan may not engage when needed. Another critical component is the coolant temperature sensor, which signals the engine control unit (ECU) to activate the fan. If this sensor is defective, the fan may not turn on at all. It's also important to inspect the electrical system, including blown fuses or malfunctioning relays, as these can disrupt power to the fan. Wiring issues can further complicate matters, so checking for any damaged or loose connections is advisable. Lastly, consider the fan control module and the fan motor itself, as defects in these components can also lead to a non-functional radiator fan. By systematically examining these potential failure points, you can effectively diagnose and resolve the issue with your radiator fan.

Why is the Radiator Fan Not Working in a Dodge Ram 3500?

When the radiator fan in your Dodge Ram 3500 is not functioning, it is crucial to address the issue promptly to avoid severe consequences. A malfunctioning fan can lead to overheating, particularly during demanding tasks like towing, which can cause significant damage to the engine and transmission. Ignoring symptoms such as a slow-spinning fan or unusual noises can escalate the problem, potentially resulting in costly repairs. Start by checking the coolant level and inspecting the fuses, as these are often the simplest fixes. If the fan assembly or fan clutch is at fault, it may require more in-depth troubleshooting. Additionally, ensure that the wiring and connections are intact, as any disruption can prevent the fan from receiving the necessary signals from the engine control module. By taking immediate action, you can safeguard your vehicle's performance and longevity, making it essential to diagnose and resolve radiator fan issues without delay.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.

Dodge Ram 3500 Radiator Fan Not Working: Causes & Repairs