A/C tune ups include the following:
Inspect fan blades
Inspect belts
Inspect electrical connections
Inspect service valves
Inspect indoor and outdoor coils
Check for refrigeration leaks
Measure refrigerant charge
Thermostat calibration if needed
inspect blower assembly
Clean condensate drain line
Monitor fan motor voltage and amperage
Inspect bearings for signs of wear
Lubricate blower motor bearings if needed
Inspect capacitor condition
Voltage and amperage reading of motors
Test compressor contacts
Inspect existing air filter
Measure airflow temperatures and pressure
Test safety controls