Performed system maintenance. Found equipment operating with low refrigerant charge. Performed leak search as part of maintenance. Found leak present at filter dryer on roof top. Need to recover refrigerant still present in system and change filter dryer pull vacuum and top off refrigerant charge. Approximately 4 lbs of 410a. Thermostat wire on rooftop has also deteriorated this can cause a low voltage short and damage more expensive components and cause a no cooling scenario. Suggest to replace the filter dryer and replace portion of low voltage wire exposed on rooftop. James returned and evacuated system Removed old filter dryer and replaced with new Pressure tested system Triple evacuated system to 500 microns Charged system with factory charge System is cooling as designed at this time but will need to return tomorrow from 12-4 time frame to replace outdoor communication wiring due to me not having enough in my truck at this time. Made client aware Replaced thermostat w