[john smith]

Thanks Creg
Yes, it is cooling the radiator.
When standing beside the car with both fans running (engine off), there is
an awful lot of hot air moving out of the engine bay.
This is a good sign that the fans are doing more than just cooling the
radiator.
If the fans are switched 'off' immediately the engine is shutdown then there
must be a large amount of residual hot air building up with no place to go.
It would certainly melt any snow accumulation on the bonnet!!!!