Hi all,
My air con has seemingly packed up just in time for the summer. There was a really bad smell in the car this morning (not me for a change) and after trying the air con this afternoon it's not blowing cold. Have the following code 

What's the best way to test the compressor, should I be able to hear it kicking in? Any other checks I can do at all? 
I did have the thermostat replaced the other day, are they in the same vicinity? (Long shot but something may have been knocked/not replaced properly etc.) 
Thanks