Upon arrival completed inspection on indoor unit. Electrical connections are tight. Blower wheel and evap coil are clean. Adjusted blower wheel, to stop screeching of metal on metal. Wheel barely scraping blower housing. Flushed drain line. Leak searched coil, no leak found. Reassembled system and proceeded outside. Completed inspection on outdoor unit. Electrical connections are tight. Washed cond coil. Found pressures of system fluctuating, suction line 85-100 Showing signs of contaminants and non condensables in system. Also unit is low on charge. System has a 35 sh. Added 1lbs 410 pressures now 110/275. 15sh. Still has fluctuation of suction line, advised customer of this. Customer declined having refrigerant rejuvenation done on system. Contactor, compressor, cond fan, cond cap all within specs. Unit cooling as well as it can at this time.