Performed preventative maintenance for air-conditioning system. Replaced customer supplied air filter (16x25x1). Inspected the gravity drain that feeds to a condensate pump. Pump is operating as it should and the drain line is clear. Inspected all the electrical components. Capacitor and contactor are both fairly worn and I recommend they be updated in the near future. Tested the amp draw from the blower, compressor and fan motor. All are operating within manufacturer spec. Tested the temperature split between supply and return. System is operating at 20° differential on a 66° day. Low voltage wire going to the outdoor unit is in poor condition. Likely to short out in the future due to exposed copper. System is operating properly at this time. Customer paid for todays ac maintenance agreement and prepaid for heater maintenance agreement. Found low voltage wire outside to condenser in poor condition. Copper wire is mostly exposed and will cause a short in the future. Recommend replacing