Cooling Fan Not Working
A cooling fan that does not run can make the engine overheat at idle or in traffic while temperatures may improve at highway speed.
Can I Drive?
fix-soon
Most Likely Causes
- 1
Blown fan fuse or bad relay
The fan circuit may not receive power.
- 2
Failed fan motor
The motor can wear out, develop dead spots, or draw too much current.
- 3
Bad temperature sensor input
The computer may not know the engine is hot enough to command the fan.
- 4
Melted connector or wiring fault
High fan current can damage terminals and wiring.
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How to Diagnose It
- 1
Command fan with AC or scan tool
Many vehicles run the fan with AC on; a scan tool may command it directly.
Tool: Scan tool if available
- 2
Check fan fuse and relay
Verify power through the fuse and relay rather than only looking at them.
Tool: Test light or multimeter
- 3
Inspect fan motor connector
Look for melted plastic, loose pins, or blades that do not spin freely.
Tool: Flashlight
How to Fix It
Repair fuse, relay, or wiring fault
Replace failed electrical parts only after checking for motor overcurrent or shorts.
Replace failed fan motor or assembly
Replace the fan if it fails direct testing or current draw is excessive.
Repair temperature input issue
Fix coolant sensor or wiring problems that prevent fan command.
Parts & Tools
Enter your vehicle on the home page to get vehicle-specific parts links.
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Related Issues
Bad Cooling Fan Relay
A bad cooling fan relay can stop the radiator fan from turning on when the engine gets hot. This can cause overheating at idle, overheating in traffic, weak AC performance at low speeds, or a cooling fan that only works sometimes. The relay should be tested before replacing the fan motor because a fan motor can look dead when the relay is not sending power.
Blown Cooling Fan Fuse
Blown Cooling Fan Fuse means the fuse protecting the radiator fan circuit has opened, usually because the fan circuit drew too much current or shorted The repair should start with power, ground, fuse, connector, and load testing instead of guessing at modules or replacing parts at random.
Cooling Fan Control Module Fault
Cooling Fan Control Module Fault means the electronic module controlling fan speed or fan command is not switching the fan correctly It can cause overheating, fan warnings, AC performance problems, or intermittent fan operation depending on the vehicle.
Other Cooling Issues
Browse more diagnostic guides in this category.
AC Compressor
Your ac compressor is the heart of your air conditioning system, pressurizing refrigerant to cool cabin air. A failing compressor will leave you blowing hot air and typically requires replacement rather than repair.
AC Compressor Car
An ac compressor car component is the heart of your air conditioning system, pumping refrigerant to cool cabin air. When it fails, your AC stops working entirely, leaving you in uncomfortable heat.
AC Compressor Cost
AC compressor cost typically ranges from $500 to $1,500 at a repair shop, including parts and labor, with DIY replacements costing $100–$400 in parts alone. A failing compressor reduces cooling performance and can damage other AC components if left unaddressed.
AC Compressor Oil
AC compressor oil is a specialized lubricant that reduces friction inside your compressor and keeps it running efficiently. Low or contaminated compressor oil can damage your AC system and lead to expensive repairs.
AC Compressor Price
AC compressor price varies widely based on your vehicle make and model, with costs typically ranging from $200 to $1,500 or more for parts alone. Professional installation adds labor charges, making total replacement costs significantly higher—often $500–$2,500 at a shop.
AC Compressor Pulley
The ac compressor pulley is a spinning component that engages and disengages the compressor from the serpentine belt to control when your air conditioning runs. When it fails, your AC won't work properly and you'll hear grinding or squealing noises from the engine bay.
Mistakes to Avoid
- Do not sit in traffic with the gauge climbing and the fan off.
- Do not replace the fan motor without checking fuse, relay, and command signal.
- Do not install a larger fuse in a fan circuit.