Introductions:
When your indoor AC is blowing air but the outside fan isn’t spinning, Outside AC Unit Fan Not Running But Inside is there’s a problem. This needs attention or it could damage your system. It can also drive up your energy bill fast. Let’s look at the real causes and what you can do about them.
1. Power Problem
Check if the outdoor unit is getting power.
A tripped breaker or a blown fuse could stop the fan.
Go to your breaker box and see if any switch has flipped.
If so, turn it back on and see if the fan starts.
If the breaker keeps tripping, stop there.
It means something’s wrong and needs a technician.
2. Bad Capacitor
The capacitor gives the fan motor the push to start.
If it fails, the fan won’t spin.
You might hear a humming sound while the blades stay still.
Sometimes, the capacitor swells or leaks, but not always.
Don’t try replacing it unless you know how.
It can still hold a charge even when the system is off.
Call someone who knows what they’re doing.
3. Fan Motor Gone Bad
Fan motors wear out over time.
If the motor is dead, the fan won’t move.
You may notice it trying to start and then stopping.
It might also get hot or make odd noises.
This part needs testing with the right tools.
Get a technician to check and replace it.
4. Stuck Fan Blades
Leaves, dirt, or small branches can jam the fan.
Shut off the power and try turning the blades by hand.
If they’re hard to move, something is blocking them.
Clear out any debris you find.
If the blades are bent, replace them.
5. Contactor Not Working
The contactor sends power to the motor when the AC kicks on.
If it’s stuck or burned out, the fan won’t turn.
You might not hear the usual click when the system starts.
Over time, contactors wear down.
Replacing them is not hard but involves live wires.
Let a pro handle that job.
6. Thermostat Not Communicating
The thermostat tells your system what to do.
If it sends the wrong signal, the inside may run, but the outside won’t.
Make sure it’s set to “cool” and the temp is lower than the room.
If it uses batteries, try replacing them.
Loose wires in wired thermostats can also cause trouble.
Try lowering the temp and listen if the outdoor unit starts up.
7. System Overheating
Outdoor units can shut down if they get too hot.
This protects the compressor from damage.
Dirty condenser coils or blocked vents can cause this.
Turn off the system and let it cool down.
Rinse the coils with a garden hose—never use a pressure washer.
Then turn the unit back on and check the fan.
8. Old Equipment
If your AC is over 10–15 years old, parts can start failing.
Old motors and components just don’t last forever.
You might notice more frequent problems.
At some point, replacement is better than endless repairs.
FAQs
Why is the Outside AC Unit Fan Not Running But Inside is?
Your indoor blower can still run, but without the outside fan, the system won’t cool properly.
It could overheat or freeze up.
Can I keep using my AC like this?
No.
It could ruin the compressor and cost you even more.
How do I know if the capacitor is the problem?
If the fan doesn’t spin but hums, the capacitor may be bad.
Try spinning the fan blades with a stick—if they move freely but don’t start, that’s a clue.
Is fan motor replacement a DIY job?
Not unless you know electrical work.
It’s safer to call someone trained.
Is flipping the breaker more than once safe?
No.
Repeated trips mean there’s a real issue.
Don’t force it—get it checked.
Conclusion
If your outdoor AC fan isn’t spinning but the inside is running, don’t ignore it.
It could be something small or something serious.
Start with simple checks like the breaker and visible dirt.
If the fan still won’t turn, get help before things get worse.
Fixing it early saves time, money, and stress later.
