Interior fan problem

[James 3006]

Hi, my qashqai has developed a  interior fan problem the last few days,  air con , heat, cold ,whichever  use there is a clicking noise coming from inside the system , does anyone have any ideas what could be wrong  please 

[Trevor]

Has anything dropped into the heater motor from the dashboard vents by the screen?

Also, remove the cabin filter and see if the vents have dragged anything into the blower motor through there