What was found
WHAT SEEMED TO BE AN ELECTRICAL BURNING ODOR DEVELOPED IN THE COCKPIT DURING LEVEL FLIGHT WITH THE ANTIICE SYSTEM (ON) LASTING APPROXIMATELY 2 MINUTES. FOUND BAD ACM AND HEAT EXCHANGER ASSY. REMOVED THE ECU ACM S/N AND HEAT EXCHANGER AND INSTALLED NEW HEAT EXCHANGER AND AN OVERHAULED ACM WITH A NEW PLENUM. PERFORMED AN OPERATIONAL CHECK OF THE ECS SYSTEM. OPS CHECKS AND LEAK CHECKS PASS. ALL WORK ACCOMPLISHED IAW MM 21-51-00 AND THE OPERATION AND MAINTENANCE SOURCE DATA REPORT 4-401 ECU.