Saab AC vent will not blow air sometimes?

I have a 1999 Saab 9-5,
sometimes the vent will blows out air sometimes they will not. The good thing is that once it blows, it blows cold ice air, and it will continue to do so until I turn the car off. Once I turn the car back on again, it depends, it may blow it may not. Anyone with an idea?
Marvin_g,
Talking about actuator; I am also experiencing a broblem with my brake system (ABS) tha pad gets hard sometimes, and the brakes tight all the time I drive burning the pads and sometimes stopping the car completely. Sometimes this doesn't happen. it this a connected problem?
I will try to press the AUTO and OFF and se what I get.
Thanks guys
I pressed the AUTO and OFF bottons and I got a zero.

Press the Auto and OFF signs together and the ACC will reset itself. If you get "0" as the reading then all is well your system but if you get a number then go to your SAAB dealer to fix the problem. The climate housing of the 98/99 models was a problem as arms and flap get broken or stuck. Some arms are available as spare parts, the only other solution would be to replace the climate housing.

The temperature sensor could also be faulty.