Unit not starting traced to degraded capacitor, not outdoor unit failure

What we found

We tested each electrical part in the outdoor unit one by one before making any recommendation.

• Indoor unit was sending the start signal correctly. The link between indoor and outdoor was intact.
• Outdoor fan motor ran when tested directly. Motor windings were sound.
• Compressor made a brief hum on start attempt then cut out. Classic capacitor problem.
• Capacitor reading was well below the rated value printed on the casing.

The run capacitor had worn down over the years. It could no longer supply enough starting torque to the compressor motor. The compressor tried to start on each cycle, drew excess current, and the overload protector cut it off. The compressor motor, the fan motor, and all other outdoor parts were working normally.

What we did

We replaced the run capacitor with one matching the rated value. The compressor started on the first cycle after the swap. Full cooling was confirmed at the indoor unit.

The unit has been running normally since the capacitor swap. The outdoor unit, compressor, and piping were all retained. The client avoided a full system replacement.

What we learned

Unit not starting — capacitor vs. outdoor unit failure.

• A worn run capacitor stops the compressor from reaching its starting torque. The compressor tries to start, fails, and the safety circuit cuts power. From the outside it looks like the whole outdoor unit is dead.
• Replacing a capacitor costs a fraction of replacing an outdoor unit. Always test before condemning the larger unit.
• Testing the capacitor takes a few minutes with a meter. If the reading is below the rated range, the capacitor is the problem — not the compressor motor.