air con not blowing cold air

[h45gti]

Evening all, decided to use the aircon today, ive had the car since November 2013 so not that long I guess, bought from an indy dealer in south London, im still kind of a newbie ( learning about faults and what  things to check prior to purchasing used cars) so didn't really think of testing/using it sooner till today.
 
Switched on the aircon but blowing hot air ( hot day today) decided to go Halfords and buy that  "EZ chill air con regas kit" managed to find the low side air pressure bit after looking like a total noob and scratching my head in the car park, checked the pressure, it was zero, shook the can and followed the instructions to refill it, I refilled it up to the green section as stated on the instructions but still not blowing cold air

Went home to check again as it was quite noisy near the dual carriage way, and at home I could hear a hissing sound coming from near the alternator/cambelt and listened carefully and checked the pressure again and veeeerryy slowly it was dropping down on the gauge. Im no expert, I have read some forum topics etc, I reaaallly hope its not the compressor as mentioned in various forums.

if I can hear this hissing noise as gas is leaking Im assuming, it COULD just be a leak right (not the worst fault??) , is it an easy/ cheap fix? I have warranty with warranty direct, ive recently got them to fix my mechatronic unit, they contributed and I ended up paying around £350 approx opposed to the £1k bill  and glad I got it sorted as the car is beautiful to drive having seen the difference. any advice much appreciated thanks all! 

[J400uk]

Check around the pressure switch as it could leak through hear and you'd probably hear a hissing noise

[h45gti]

Cool thanks I will check that but first.... where is the pressure switch  yes im a noob still learning

[Sati2010uk]

i sent my car to main dealer and below is the reply i got from  adealer in twickenham

'the air con will not blow out cold air because the main compressor and dryer are not working hence there is nothing workin to compress it to make it cold'.  will cost 1100 to fix ... ( you must be joking lol) 

i will do my research elsewhere and get this sorted for around 400 id day. hopefully ill post on here when i find someone

[h45gti]

I checked something, might be the pressure switch you mentioned, heres a pic below


that bit with the wire covered in black?




I touched it (  ) and almost immediately the hissing started and little farty sounds like pfrtt hisss    seems like its not secured IMO or something like a washer or seal is worn, or even the electrical bit that's coming from the top maybe that's got something to do with it? this is fun poking around the car