Just one point to add to what Mike has written, disconnect the battery negative wire before you disconnect/ remove the aircon control panel otherwise if you pop the key in without the panel connected the car will throw an airbag fault which requires a main dealer reset unless you have or know someon...

Just solved this same issue yesterday. Its likely not the fan. Vida should show relay signal missing if you do a new scan. Its probably the purple wire. Look for 2.8v where the loom enters the junction/fuse box, probe the plug whilst commanding fan on. If yes, test at the fan plug. Its losing the si...

I just took a quick video showing how I tracked mine down.
Disconnect battery if you resort to my method,
I think a decent meter should be able to track the 2.8v signal though.