Ventilator stopped

Hi guys, my wifes car 1.9tdi roomster 2007 has a problem with ventilator.

1 week ago, her car stopped, and after that it was not possible to turn on ventilation on any possition.

Next day everything started normally.

Today I started car, and everything worked fine. I turned off car for a minute, and after that same problem came. I left car for 3 hours and I tried again - nothing.

I have two small kids and she can't drive them without ventilation and air condition.

Is it possible that it is some fuse or relay, or something that I could fix it easily?

Sasa