1 system A/C tune-up for Apt C. Found no filter inside the furnace are and dirty blower wheel. Install filter, and clean the dirty condenser coil. Found burnt/pitted the main switch, found a weak starter and low on Freon. There were no caps on the connection for gauges. I added 2 brass caps. The owner just wants to add Freon and compressor saver. Installed compressor saver and added 1 lb of Freon. The system is cooling at this time