Arrived on site diagnose a system for a blank thermostat. Upon arrival spoke over with client on what is going on. He stated system would cool but randomly shut off and turn back on and it would do it repeatedly. Went to inspect indoor equipment. Found secondary line has a safety float switch and it had water in it tripping safety switch opened up system. Found filtration really dirty and clogged up. Blower wheel dirty. Evaporator coil dirty and debris. Went and located primary drain line connected to sink drain line. Unhooked it and found sink drain is completely clogged up. I Not allowing system drain water. Client stated he will take care of sink drain and get it cleared out himself. Client did declined recommended work at this time but want to renewal monthly ESA at this time. Went and did Ac maintenance. Client as ok with this being his first maintenance of the year. Did indoor inspection. Found filter super long over due creating restriction in system and stress on components. R