Thanks Rich and Richard,
It has been hot in Sussex so maybe that is the explanation. Still, the only way to stop the fan is by engaging the general cut-off switch (red/orange plastic lever between the rear footwells) and vice - versa - fan comes on immediately cut off is disengaged. Never heard of the ‘otter switch’ - but I am grateful for that information to pass to the garage. And for the suggestion re fan relay. We’ll see!
