Arrived on site to perform spring tune up on a 2001 system. Condenser located in back yard. Furnace and evaporator coil located in attic. Client or Tenant stated no issues. had tenant cycled cooling mode to ensure system operating. Inspected out door unit. Washed condenser coil inside and out. Checked electrical compartment and components. Checked amp drawls o. Compressor and fan motor. Checked refrigerant pressure. Did indoor unit inspection. Replaced filter. Checked electrical wiring, connections, circuit board, and components. Checked blower assembly and evaporator coil. Checked secondary drain pan, drain lines, and temperature split. The summary of findings are as followed. Cycled system to ensure systems is operational. Condenser 1. Condenser is starting to corroded at bottom of the condenser coil. 2. Thermostat wires are exported on line set that run into home and electrical compartment as the whipper is not coving thermostat wires completely. 3. Line set has no isolation