My car got this problem. please quote me and expected budget altogether:

1 - Sometimes its working flawlessly, and sometimes if switching on the aircond, there was like a vacuum problem, its like the car going to shut off the engine and the rpm drop suddenly below 1k rpm. (Normal condition, 1.3k rpm set up if switching on the aircond). And noted that when this happen, the voltage meter shows drop a little bit of volt reading.

2 - My original blower really slow. If you turn to level 3, which is the highest blow, the power of the blow is equivalent to level 1 in Kancil/Myvi. I even change to a new blower couple of times but i guess its the blower already OEM's spec as all my fren using the car experienced. Any way of upgrading to a more powerful blower? change the wiring or bigger motor of it with a little bit of modification?

3 - The sensor always got sound tick tick tick a few times and happen all the time in an interval of 20-30mins once. And everytime that happen, aircond not cold.

Note : I already upgrade my condenser to a bigger one and use aftermarket fan, small fan but more blade and installed 2 of them.

Charade Aura 1991 - Engine converted to CB70.