TIMS showed rear M1 car air-con sets #1& #2 faulty. Staff(BBT) checked and confirmed faults. Unableto reset both sets air-con. Car was warm. TC feedback again at YWT2 that air-con faults at rear M1 car cleared. Staff(K  ~~~~~ 1520 TIMS showed A/C 1 & 2 faulty. Staff(BBT) confirmed faults. Unable to reset both sets air-con. Car was warm. TC feedback again at YWT2 that air-con faults at rear M1 car cleared. 1520 1-1, 1-2 Having compressor fault Temp 27.9'C.  1520 A/c 1 CFC-1 & CC1 failure. #1520 A/c 2 CFC-2 & CC2 failure. Checked both CF rotation, ohmic value & meggar - OK. Both CC ohmic value & meggar checked - OK. Freon pressure checked - OK. OPS 20 raised to follow-up.  Chan SW/Hanafi 44202 To continue rectification.  1520 A/c 1 MCB unit swopped to #1519 A/c 1 & LVD PCB swopped to #3520 A/c 1. Function check & monitor A/c cut in/out operation - OK. After 5 hrs of monitoring, during depot shunting, #1520 A/c fault occurred. OPS 30 raised to follow-up.  Selvan 44202 To follow up.  1520 A/c 1 CFC2 A2 LGD to pin 5 at CN2 - OL (cable side of cannon plug). OPS 40 raised to continue rectification.  Chan SW/Hanafi 44203 To follow up.  1520 A/c 1 cannon plug Pin 5 to saloon A/c 1 CN1 connector Pin 32 checked - OK. Further check/found saloon A/c 1 CN1 Pin 32 to A/c panel not seated properly. Re-secured & function test - OK. Monitor for 2 hrs - OK.  Selvan/Lee PT/Alcus 44203