Complete 1 system a/c repair and preventative maintenance check. Changed filter. Installed union on drain line and cleared line. Found no overflow protection switch on system. Recommend installing overflow protection to serve as a backup to primary water safety and to help protect furnace from potential water damage. Tested mechanical and electrical components, found electrical pitting present on main electrical switch, recommend repair. Recommend installing a hard start kit to reduce load on compressor so it starts smoother, runs smoother and therefore lasts longer. Recommend surge protection to protect equipment from power surges. Chemically washed condenser coil. System is cooling at this time.