What was found
CUSTOMER SQUAWK OF NO HEAT IN CABIN AREA. INSTALLED MODIFIED VCSC CONTROLLER FROM ENVIRO SYSTEMS INC P/N 1300640-10 S/N 00216. OPERATION CHECKED SATISFACTORY. AIRCRAFT FLEW ABOUT 2 HOURS AND CUSTOMER SQUAWKED THAT THERE WAS NOW NO COCKPIT HEAT AND WINDSHIELD FOGGING. PERFORMED DOWNLOAD OF ECS SYSTEM AND FOUND THAT THE INSTALLED REPLACEMENT MODIFIED VCSC CONTROLLER WAS SHOWING THAT THE A/C HIGH PRESSURE SWITCH WAS DISPLAYING INVALID AND LOW PRESSURE SWITCH READING HIGH PRESSURE ON DISPLAY. INSTALLED ANOTHER MODIFIED VCSC CONTROLLER P/N 1300640-10 S/N 00223. OPERATIONAL CHECKED SATISFACTORY AND BOTH SENSORS READING NORMAL.