Completed full system tune up. Checked all amperages, volts, and pressures on system. Customer still dealing with drain line upstairs backing up we finally found where it drains outside. I poured a quarter of a gallon of drain solvent down the upstairs unit and flushed it with water and sucked it out in the outdoor pvc if customer continues to have issues we may need to redesign the drain line. I also replaced a failing capacitor on the upstairs unit that I found. Both units are operational at this time.