have just purchased a 2010 fiorino and the blower doesn't work on 1 2 3 or 4.
I have seen i need to check fuse 8 under the bonnet.
The number 8 slot is empty. I tried a fuse in it and it made no difference ??
I have also read about the resistor and plug etc.
Any help greatly appreciated thanks.

Hi m8, I had that problem too, after practically dismantling the dash and trying everything possible. It turned out to be the heater motor. It was kaput.
So the only thing for me to do was replace it. I couldnt find a second hand one so I had to buy new. Cost me the guts of 250 yoyos.

Have a look here
https://www.fiatforum.com/fiorino-iii/423433-heater-1-2-3-4-a.html

Just sorted it cheers. A tap on the fan box and it started working