Customer called for system cooling but wouldn’t shut down at the customers set temperature. I found that the customer has a nest thermostat that they don’t fully know how to operate. It was set for home learning mode where it makes a schedule based oh the temperature you adjust to. Customer just wanted a standard setup with no schedule. I removed the schedule and the system was no operating as desired. Found no issue with the thermostat or that it was cooling beyond the setting. I then proceeded to perform the maintenance. Inspected all the electrical components. Confirmed proper high and low voltages. Tested the temperature split between the supply and return. System was operating at a 19° differential. Tested the amp draw for the blower, compressor and fan motor. All were operating within the manufacturer specs. Customer replaced the 16x20x1 air filter. System is operating properly at this time.