Arrived to remedy an inoperable air conditioning system. Upon inspection of the system found condensation from the intake for combustion air had fouled the add a line kit. Performed diagnostic and found that the system would operate without the thermostat and add a line. Talked with homeowner about repair and replacement solutions. Homeowner would like to have a WiFi capable thermostat installed. Since the route for the thermostat wiring was open and available decided to not deal with the mess that the previous wiring was and ran new thermostat wiring. Secured all wiring out of the way and installed thermostat. Cycled power to the system and tested operations. Air conditioning system is operating properly at this time.