What was found
FLT 119 IN CRUISE, EICAS MESSAGES "L GEN OFF" AND "L AC BUS OFF". DISPLAYED WITH THE CORRESPONDING "L GEN OFF" AND "L BUS OFF" LIGHTS ILLUMINATED. A GENERATOR RESET DID NOT CORRECT THE CONDITION. ATTEMPTS TO POWER THE L AC BUSS FROM THE OTHER POWER SOURCES WERE NOT SUCCESSFUL. FLT DIVERTED AND LANDED WITHOUT FURTHER INCIDENT. MX REPLACED GROUND POWER EXTERNAL CONTACTOR K114, CURRENT TRANSFORMERS T112 & T127, AND BUSS TIE BREAKER C902, WITH NO EFFECT. ALSO, PERFORMED FIM 24-22-00. NO FAULTS FOUND. MX FOUND WHAT WAS BELIEVED TO BE A SHORTED AFT GALLEY FEEDER WIRE, W3538-0005. WIRE STOWED IN PREPARATION FOR A FERRY FLT WITH THE WIRES DISCONNECTED, THE AC BUSS ISOLATION STILL OCCURRED. PROBLEM ISOLATED TO THE LT TRANSFER BUSS & CAPTAIN'S CDU. WHEN CDU REMOVED, LT AC BUSS OPERATED OK. DETERMINED THE CAPTAIN'S CDU CIRCUIT BREAKER MALFUNCTIONED. REPLACEMENT OF CDU & CIRCUIT BREAKER FIXED LT AC BUSS TIE. ACFT MX FERRIED WHERE WIRE W3538-0005 CHECKED OK & REINSTALLED, AND THE AFT GALLEY COFFEEMAKERS & AFT GALLEY POWER ELECTRICAL LOAD CONTROL UNIT REPLACED.