i went to a good AC Wala today, indeed the Thermostat Sensor isnt working.
It is a RTD (Resistive Temperature Device) type sensor that trips the AC Compressor at the correct temperature. The current one was not working at all, hence compressor all the time ON.
We tried to replace it with a Kabli one from his used-parts treasure, some didnt work, and some tripped the compressor too early. So the current status is now he replaced the sensor with another one but its tripping the AC earlier than needed, which is resulting in cooling less than the standard level.
I will look for a new sensor tomorrow morning.