Brought the car 2 years ago... Aircon needed regassing, had its reassess yesterday at quick fit everything was fine. No leaks etc, but the aircon pump (compressor) isn't kicking in.... Checked the fuse and that's fine

Broken cable going to the pump?

On my old vectra the earth wire had broken so it wouldnt kick in

Had this problem with mine, went the same way and got it re-gassed. They found after that it still wasn't working and saw strange voltages of 10V in nearly all of the connecting wires. Turns out instead of a new £300 compressor, it was a £20 wiring fix. My Air Conditioning is now working perfectly, better than I had expected if i'm honest.

could be worn out, the pulley works using a viscous clutch

Does the aircon compressor on a fabia not constantly run anyway? I dont think it kicks in either as its constantly running. Its eiither worn out, working fine or they need to vacuum empty the pipes and refill with the correct amount of gas.

Well first thing that's getting done tomorrow is a voltage test to see what volts I'm getting, if there's nothing then surely it's a broken wire.

Yes the pulley on the compressor is going round but when you put the aircon button on in the car, you can't hear the revs drop.... And obviously the cold air either lol.