A running condenser fan with a silent compressor can confuse and frustrate homeowners. The outdoor fan blades spinning might give the impression the system works fine, yet the air remains warm indoors. Understanding what causes this mismatch will help identify solutions faster and avoid serious system damage. Fan Works, Compressor Doesn’t? Common Causes AC Compressor Failure Signs When Fan Still Works Faulty Capacitor The most common reasons a compressor doesn't engage is a failed capacitor. The capacitor stores and delivers a quick burst of energy to start the compressor and fan motors. A defective capacitor may still let the fan spin but fail to jump-start the compressor. Replacing the capacitor typically restores normal function. Burned-Out Compressor Compressors deal with high pressure and electrical loads. Over time, stress or overheating can lead to burnout. A burned-out compressor won't make noise or activate, even though the fan keeps running. Replacement becomes necess...