Hi all.........my aircond system have gave me problems yesterday. Its started when I refill aircond gas at one of 'kampung aircond repair workshop'. My aux fan suddenly spin at very high spin nonstop. What I did is do my research in this forum and very fortunate to find three possible solution. First, check your heat resistor in case it fail to send the right signal to aux fan to spin at what speed. But then, some our fella forummer said heat resistor has got nothing to do with aux fan. Heat resistor only respond to blower under the dashboard. Second, check your thermostat whether it is ok or not. In my case I suspect something that got to do with gas pressure. Once I do a more thorough research...I found an info that BMW aircond system should be fill with exact amount of gas. It cannot be less or over fill up. If over fill up then it will caused higher pressure which then will cause aircond to malfunction and only blow warm air. Higher pressure will also caused aux fan to spin at maximum speed continuously and in some cases it spin nonstop even if we switch off the engine. This problem if not solved properly and immediately will escalate to many other problem. for instance it may caused your battery to flat and many error code will appear. So what I did is release some gas from the system manually and it is ok immediately after that. Thank you to all sifus......sharing is caring. 
