Ventilation

Prima - I'm in Berlin and I don't have a manual and nothing -
the windows are covered , warm is not
ventilation does not ventilate - fuse is OK ( display is also on )
but the fan motor does no more muck -
one of the relays in front of the fuses, right?

But which one?

I didn't even have a multimeter - crap

Can anyone tell me which relay is probably defective?
or anything else?

Thank you from Berlin

Christian