towbar module

[Lingo09]

i have installed a towbar and used a towbar module from a scrapped berlingo into mine.

i have put in a 40amp fuse in the fusebox under the battery.
so the wire went live.
measured 12v going into the module.

the berlingo was prewired for a towbar. so the module was just to plug in.

Yet the electric does not work.
i drove to a dealer but he plainly said over the counter it does not need activation because its a older car.

Is this correct ? 
or was that guy wrong and do i need activation in the cpu after all.

its a berlingo b9 2009 multispace

its a 7 pin towbar

[shtu]

The car will need coding for a factory towbar module.

https://www.youtube.com/watch?v=--w0tF4ZT1U&t=1812s

[evdama]

Ask price for doing it first.
Weigh up against an afternoon of your time and a 20 quid relay.