Seat Inca1.9sdi doesn’t start. What can that be?

Hello, when I had to go with the car (Seat Inca) tonight he did not jump on. All control lamps go, also blowers etc. Vorglühlampe etc…. Then on the 2nd attempt he went on. But I wanted to be sure, because I drove a few meters up or to a mountain, turned off the engine, and again tried. Again nothing, had to wake up, therefore I had him roll short hand. Now my question: Is the starter that? That is broken? If I have the ignition Turn on the blower runs quite normal, as soon as I turn around the key to start the ventilation goes off ! Short circuit ? Mass cable of the battery I have already checked ! Today it was the first time colder at night, should certainly not be the battery ? Although I was running a track when the car ran, now again the same. So battery should have charged! Does the starter have a short, or defective ? Can it be anything else ? Thanks FG Marc