How wire a 13pin tow bar socket from a 7pin socket!

How to wire a 7 pin socket on the back of the defender to a 13 pin socket. The old one is all corroded and I believe it’s not helping the lights work correctly.
#towbar
#defender
#towing

[@deanh3741]

Just be aware for MOT 7 pin is a “visual inspection” whereas 13 pin is an assessed item, 7 doesn’t include a reverse light but 13 does and therefore you could fall foul come the MOT

[@Allthingsdefender]

I didn’t know that thanks for the info I shall get that sorted.