I was going to replace the fan, but after further trouble-shooting, it was actually just the relay that was faulty..
Anyway, I made use of the chance to tidy up the front - Did some rewiring and securing the air-con fan (It was really loose and was making noises before)
Although it cant be seen after the bumper goes back up, but it feels good to know that wiring are in order and the fan is secure :).
Anyway, some simple air-con trouble shoot tips before going further.
1) First check if the fuse are blown:
Under dash - fuse 13 (7.5A)
Under the bonnet - fuse 35 (20A), fuse 39 (50A) & fuse 41 (80A)
2) Next check the two relays - one is for the compressor and the other is for the fan.