Got Bert's fresh air fan running, direct from the battery.
Run smooth once wasp nests were blown out with air line
So Earth for fan,
Also Brown wire from fan into heater box. 2 x Green /yellow from heater box ? To switch I guess. Little Silver coil of wire inside heater box, once flexi duct was removed.
Looked in both my manuals and no fan on wiring diagrams.
Would anyone please have a wiring diagram with it included.
Thanks.

Whitehillbilly