Performed ac diagnostic on 26 yr old split inter-city unit. Found blower making a lot of noise. After inspection of blower compartment found water in blower and then inspected ac indoor coil found system freezing up. Appears to be draining correctly but can’t tell for sure. Outside found more frozen lines and found system low charge 44/165 coil is freezing. Could be low charge also could be bad metering device. Went over options with owner. Went with charging system and signing up on the maintenance plan. Charged system pressure got better for now. The refrigerant went somewhere, so the question is where and how fast. Only time will tell. But now as a member we can check and see during our visits.