Performed diagnostic on 1997 package unit. Homeowner wanted to see how system was operating. Thermostat on wall is no longer operational. It is receiving power and sending out commands but the display no longer works. Jumped into the attic to access ductwork. Found return duct completely off of the return can, system was sucking in air from the attic. Ducting is in fairly poor condition, and system is running on flex duct as well as rigid ducting. Attic insulation levels are really low. Condenser fan motor in package unit is completely seized up. All primary and secondary motor controls appear to be in good condition and in range. Could not test refrigerant levels or system amps due to condenser fan motor being seized up. Went over findings and recommendations with homeowners. Ultimately homeowners want to just replace the system and ducting, but they have to talk it over first. System is not operational upon departure.