Suzuki SX4 only cold air driver side

Hello, I have the problem since today on my Fiat Sedici (is a SX4) that only cold air comes out on the driver’s side. Of course the heat exchanger will have something, but what is still striking: the left nozzle is also being flown since today. So no matter what I put the air conditioning automatic (foot or disc) the left nozzle always gets air. All the others are just as the air conditioning automatic says that. Except for me this has only now noticed, because it gets colder and you brew the heating. Is it possible that the heat exchanger would be closed for a long time and the ventilation is another mistake…. Does anyone have any instructions to change the cooler? Should you still try any magic agent? Shouldn’t it be a real shit to change the thing….