1 system ac tune up complete. Didn't change filter, left customer with replacement. Added chlorine tablets to evap coil drain pan. Found evap coil door came loose, sealed it up for maximum airflow. Found very little insulation on outside suction line that was old and breaking down. Cut off old insulation and put new insulation on suction line outside. Found voltage absorption system running very weak, recommend repair. Found wasps living in condenser coil, removed and killed them for customer. Chemically washed condenser coil and applied rust proof waxing. Found no surge protection, recommend adding on to protect unit from lightning strikes and power surges. System operating at this time.