Trailer lights not working - Is there a fuse?

[Magoo0853]

In Melbourne Australia, with CX-5 MAXX Sports 2.2 diesel auto purchased July 2012, with dealer-installed Trailer kit. In Aussie, we call it a tow bar, not a hitch, but same thing. The trailer lights stopped working recently, and as they were old, I replaced with LED variety. Still not working. I ran 12V down each pin on the trailer connector and all lights work as they should, so the Trailer wiring is fine. Can't get any voltage on car connector though. Here the connector is a 7-pin flat connector, but has an extra Grey and White pair of wires not involved with the 7 pin connection. Perhaps it's a smart powered connector? The white wire joins the the ground pin going to trailer.
The harness has been tapped into a loom directly behind spare tire. Looks like strip the insulations and solder, then tape.
It seems we may have a blown fuse, but have checked all 'rear outlet' fuses, and rear power outlet is working. If it's a fuse, where is it?
I'm moving house next week and would prefer to be legal. Ideas?

 

[Kedis82ZE8]

If they used the factory kit it appears there is a jumper harness in the engine bay with a fuse. Check out install doc below:

http://ep.yimg.com/ty/cdn/yhst-24809172479195/cx5trailerhitchharness.pdf

 

[Magoo0853]

While the installation looks non quite the Mazda kit you mentioned, it turned out to be a fuse in some non-typical location. Popped into the dealer service dept and got a quick fix. I tested all fuses under bonnet and inside near foot well but I couldn't find it...�� and thanks for your input.