Its not malfunction, the setting of thermostat must be at maximum due to this, your evaporator coil becomes iced & then the A/c throw becomes low, low & finish! Just go to any A/c wala, he will set your thermostat at its original flow so that you can get good cooling & it should give a time gap too so that it doesnot gets iced! Hope you understood.
Cheers,
Abbas Ali Abbasi