Thank you very much kh904.
I did manage to get the offending flap motor out in the end.
Luckily It was on the passenger side. By removing the glove box, heater motor and various other parts, we found the flap motor and unbolted it, it was mounted on the side of the air distribution unit.
The motor was working perfectly but the bracket it was mounted on was broken. A spigot which mounts a sprocket gear had snapped off. The gear engages with an air box flap for the passenger side.
I found it difficult to source a new part so tried repaired it using Araldite and a V shaped steel plate on the reverse side.
We put everything back together under the dashboard and tested it, it worked fine...and no more clicking. 😊
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