TC reported air-con fault at front M2 car. Staff (CBR)checked and confirmed #1 set faulty. Car coo ling. The air-con cabinet was unable to open due to faulty l ock. ~~~~~ 2656 TC reported A/C 1 fault. Staff (CBR)  confirmed #1 set faulty. Car cooling. The air-con cabinet was unable to open due to faulty lock.  2656 A/c 1 found CCI faulty. Tightened base connection & CN2 at U/F condenser unit. Monitor & no A/c fault was detected. Saloon temp. 24'C & cubicle lock checked - OK.  Chan SW 44243