2505-102 Outdoor Axial Fan S4E450AU0337 drives condenser airflow across the outdoor coil on Classic Series and ESP Plus residential split ducted systems, rejecting heat from the refrigerant circuit to maintain rated cooling and heating capacity at all operating conditions. This assembly uses a 4P-pole AC 1 Phase AC axial fan motor (S4E450AU0337) matched to a 8uF run capacitor -- when the outdoor fan fails, condenser coil temperatures rise, triggering high-pressure faults, compressor lockout, and in severe cases compressor damage on the hottest days when cooling demand is highest. Isolate power at mains before replacement -- live work on outdoor fan assemblies is dangerous and must only be performed by a qualified technician.