Did you check the right hand side panel? There are two plugs with caps on, one is a 3 lead the other a 4, most just connect to those. You would have to remove the little black plugs but need to find the pin connectors online, search 'live switch', and it should come up on the forum.
Plug under the seat is for diagnostics only. I used the 3-pin plug by the battery for my GPS. You can either buy a mating plug for it (it's a Sumitomo plug) or you can tap into the wires using positaps.
I noticed this link works now, a few weeks back clicking links would just take you back to the front page.
The wonderful administration must have worked tirelessly to fix this, thank you!
The Tenere is so easy to add electrical do-dads with its pop off side cover a battery access. I added a fuse block under that cover which makes the job of adding stuff so simple.