1. Visually inspected condenser coil for debris/ dirty. 2. Inspected condenser fan motor. 3. Inspected condenser fan blades. 4. Inspected/ cleaned wiring connections. 5. Tested compressor/ condenser fan motor capacitor. 6. Checked compressor amp draw. 7. Checked condenser fan motor amp draw. 8. Inspected / replaced return filter. 9. Inspected return plenum for debris/ dirty. 10. Inspected evaporator coil. 11. Inspected blower motor/ blower wheel. 12. Checked blower amp draw. 13. Measured temperature differential from supply to return. 20 degrees measured. 14. Inspected drain lines and treated to prevent blockages 15. Washed condenser unit to promote heat exchange Upstairs unit bad compressor capacitor. Informed customer of possibility of unit failure due to capacitor failure. Customer wanted to monitor the capacitor and proceed if it gets worse or fails. Notified customer of temperature sensor with dead batteries. Customer replaced batteries error went away.