What's with the white smoke from the car air conditioner?

It is true that the evaporation box is blocked by ice. The reason is that the pressure switch of your air conditioning system is broken. A normal air conditioning system will stop the compressor when the pressure is too high. If the pressure switch is broken, the air-conditioning controller can't receive the pressure signal of the pipeline, and the compressor will keep working, resulting in too high pipeline pressure and the temperature will be as cold as a refrigerator. In fact, the air-conditioning evaporation box inside is frozen, so it's lucky that the pipeline didn't explode. Go check it out.