Performed preventative maintenance on AC system. Inspected filter, blower assembly, motor, electrical components, evaporator coil, drain and overall condition of equipment. Inspected condenser coil, compressor, capacitor, contactor, fan motor, and operation of system. Capacitor was weak and I recommended that it be changed before it fails. Capacitor was reading 28/45 & 1.8/5 which is way below the recommended threshold of 6%. Customer had me replace it. I changed out the capacitor, then checked thermostat operation, wiring, amps, temperatures and pressures of AC. System is cooling properly within manufactured specifications at this time.