My aircon stopped working a couple of weeks ago, the day before it stopped working it was fine, was nice and cold then the next day all it did was blow out warm air. When i turn the aircon on now, the thermofan comes on as usual and I can hear a noise, sounds sort of like a rattling or the sound of gas coming out of the front left of the car. I checked the pipe with the red knob and glass window on it, I could see a a liquid flowing through it which im guessing is normal. Does anyone have any idea whats wrong or if its as simple as getting the system regassed? Cheers.