What was found
DURING TRANSIT CHECK, THE TRANSFER BUSS OFF LIGHT TURNED ON WITH APU AND EXTERNAL POWER. MAINTENANCE PERSONNEL PERFORMED BITE TO GCU AND BPCU IAW FIM 24-41 TASK 801 PROCEDURE, DETECTING THAT TRANSFER BAR DID NOT FEED ELECTRIC CURRENT DUE TO THE LEFT GENERATOR CONTACTOR C801 WAS FAILED; SO THE CONTACTOR C801 WAS REPLACED IAW AMM 21-21-41, TESTED CORRECT.