hi peter i don't know it this helps but i have had a couple of problems that might relate one was a vw sharan with fans on all the time narrowed it down to a faulty relay module the contacts within the relay were shorted.
the other was a cooling fan circuit fault on a vw passat but also logged faults on multiple circuits and that was THE 10Amp fuse that normally blows with the engine stop valve.
hth a little martin