When your outside AC unit’s fan fails to run while the inside unit is operating, it can lead to inefficiency and potential cooling problems. This guide outlines common reasons for this issue outside ac unit fan not running but inside is and provides steps to diagnose and resolve it effectively.
Understanding the Issue
Why Is Your Outside AC Unit Fan Not Running?
Several factors could cause the outside AC unit fan not to run while the inside one does. Identifying the root cause is crucial for implementing the correct solution.
Common Causes of Outside AC Unit Fan Not Running
1. Electrical Issues
a. Tripped Breaker
Check the circuit breaker associated with your outside AC unit. A tripped breaker can cut off power to the fan motor, preventing it from running.
b. Faulty Capacitor
The capacitor provides the initial electrical boost to start the fan motor. If the capacitor is faulty or worn out, the fan may not start.
2. Fan Motor Problems
a. Motor Overload
An overloaded motor due to excessive dust, debris, or mechanical issues can cause it to overheat and shut down. This often results in the fan not running.
b. Motor Failure
If the fan motor has failed due to age or wear, it will need to be replaced to restore proper operation of the outside unit.
3. Control Board Issues
a. Faulty Relay Switch
A malfunctioning relay switch on the control board can prevent power from reaching the fan motor, causing it not to run.
b. Wiring Problems
Inspect the wiring connections leading to the fan motor. Loose, damaged, or corroded wires can disrupt the electrical flow and prevent the fan from operating.
Steps to Troubleshoot and Resolve the Issue
Step 1: Check Power Supply
Ensure that the circuit breaker for the outside AC unit is not tripped. Reset it if necessary and monitor if the fan starts running.
Step 2: Inspect the Capacitor
Carefully inspect the capacitor for signs of bulging, leaking, or other visible damage. If it appears faulty, replace it with a compatible capacitor.
Step 3: Examine the Fan Motor
Manually spin the fan blades. If they move freely, the motor may not be receiving power or could be overloaded. If the blades do not spin freely, the motor may be seized and require replacement.
Step 4: Test the Control Board and Relay
Use a multimeter to test the relay switch on the control board for continuity. Replace the relay if it fails the continuity test or shows signs of damage.
Step 5: Check Wiring Connections
Inspect all wiring connections leading to the fan motor for tightness, corrosion, or damage. Repair or replace any faulty wiring connections as needed.
Conclusion
Addressing an outside AC unit fan that isn’t running while the inside one is requires systematic troubleshooting to identify and resolve the underlying issues. By following the steps outlined in this guide, you can often diagnose the problem and restore proper operation to your AC system. If troubleshooting proves challenging or if components need replacement, consider seeking assistance from a qualified HVAC technician to ensure your system functions efficiently.