Ford Focus MK3 aircon not working

[Harry you Potter]

I have a Focus MK3 petrol 1.6 and it needs the aircon regassing as it blows warm. I booked it in for a regas which it’ll go in for Wednesday.

Today I noticed when I switched on the aircon the revs don’t fluctuate or anything like that. On my previous cars when I switched on the aircon the revs would fluctuate whilst the pump started up.

Could this just be because it’s empty or an issue with the compressor?