got an RR Classic today and its in pretty good condition, needs a couple of things doing but nothing major, anyway ive noticed the heating controls are a little strange, air will blow out of the top vents facing the windscreen but when you set air to come out of the vents facing the passengers the flow is rather weak, well next to nothing really, also the fan continues to blow air with the switch in all positions except when you switch it to the Air Conditioning snowflake symbol and then the fan turns itself off and doesnt blow cold Air Conditioned air, any ideas what it might be?.