Fine for running a broken car's air conditioning?

If your car's air conditioning is broken, technically there's no fine just for that - what matters is whether the vehicle passes the periodic technical inspection, and that's when you could have problems if the climate control system isn't working at least minimally. The most practical thing is to get it fixed before your next inspection because they check if it works during the tests, and if it fails there it complicates everything. If you've already passed inspection recently with the AC broken, they won't prosecute you retroactively, but it won't be long before you need to renew your registration.

A broken car AC won't get you a direct fine from the police, but things get tricky when your periodic technical inspection comes around. Then yeah, if the system doesn't work at least minimally, your car can fail. And then you've got another problem: if you're driving around without AC and you've got small kids in the car on hot days, that can invite reports for neglect or endangering minors.

Now, the big detail a lot of people ignore is that some liability insurance policies can create complications if you have an accident and your car has completely broken safety or comfort systems. It's not illegal to drive with a broken AC, but they can claim you neglected basic maintenance and refuse to cover it. So the trick is not to let it go - get it fixed before the inspection and avoid the hassle.

A broken air conditioner won't get you a direct fine from the police, but people are right that the problem shows up on the technical inspection - the air conditioning system is mandatory there and you can fail. What I see a lot is people driving around with a busted AC thinking it's just annoying, and then they get a shock when the inspection happens.