Performed AC tune-up on a Carrier straight cool system. Checked the electrical, mechanical and performance systems of the unit. Cleared, cleaned, flushed and treated the drain line and cleaned the exterior of the furnace. I replaced the high voltage wire nuts with a Wago wire connector. Also found the pressure switch wiring was rubbing out on the inducer motor. I secured the wiring to prevent any electrical damage. I also found there is no water safety switch on the secondary drain line and the outdoor fan motor is showing wear and tear. No other major issues were found. The system is operational at this time.