[ebid]

Black-yellow cable from rear third of harness duct. See green circle in picture.
Single pin plug connects both ways but make sure it's completely seated.
Note that probably you have several sockets broken and separated from cable duct, specially the gray ones, and cracked cable insulation. They should be repaired/replaced.

 

[dblsix]

Thanks @ebid. I was out there last night and sure enough with a fresh set of eyes I found it in 2 minutes. As you said, there are a few broken clips which I'm taking care of as we go. Slow and steady.....

Cheers. 🍻