Well that's chucking filly...
When I tried my air-con I couldn't get the compressor to kick in. According to my paperwork the last time the air-con was serviced was in 2004 by the original owner. So today I took it to my local to have it checked over. They pulled 200g of gas out and recharged with 750g of R134a with some fresh oil and it never worked.
They noticed a broken wire at the compressor (I had seen this broken wire and thought it was a radio suppressor and decided to repair it at some point in time but it was still on my list) The mechanic repaired the wire and I now have freezing cold air-con. Shame the sun's gone now