Performed 1 system cooling diagnostics on the upstairs AC system. I found that the drain line water safety was dripped due to the drain line having almost no slope and running up under the supply plenum because the evaporator coil was installed backwards/ facing the roof line. I rest the drain safety switch and the system ran. Previous tech diagnosed the system having a refrigerant leak near the end of last summer. The unit is 13 years old and runs on r-410a and parts (evaporator coils) are obsolete. I also found that the supply plenum has holes in it and is leaking conditioned air into the attic. I advised the homeowner that if the AC coil unit got replaced we could install the new evaporator coil the correct direction and as slope to the drain line and install new plenums. I also gave the homeowner the option of me to remove the inline water safety switch all together so it would stop tripping; but he would be left without flood protection. The homeowner declined all options and wan