Need help on Installation of Trailer Hitch Harness Kit

I installed the MAZDA OEM trailer hitch on my 2014 CX5 and now am attempting to install the OEM Trailer Hitch Harness Kit (part number 0000-8E-R04). I am stuck on step 13 - Disengage Secondary Lock on Rear Junction Connector. You can see the step in the instructions located at http://ep.yimg.com/ty/cdn/yhst-24809172479195/cx5trailerhitchharness.pdf. I can't figure out what the secondary Lock is and how to disengage. Has anyone done this, or can give some suggestions? I tried to put the wire into the appropriate location, but it does not lock into place, so I think that there is something with the secondary lock.

I noticed on Youtube there are installation videos of other vendor's hitches and wiring harnesses and they all see to be much easier to install than the Mazda OEM parts. Hopint to get some help from this forum.

That was the part that got me as well. I fiddled with it for a very long time. Finally I made sure I had identified the correct wire coming in to the other side of the connector and CUT it. Yes, I felt terrible but I am over it now. I striped the wire and fastened it to the wire in the Harris with a wire nut.

All you are doing there is getting a source of 12 volts.

Btw. There are three alternatives. Run a wire under the car to the front and connect to the battery. Run a wire to the fuse box by the drivers left foot and find 12 volts. Run a wire over to the power connector in the back on the right.
BTW I do think it is worth the trouble. With this setup if you get a short in your trailer lights you don't take out your car lighting or electronics.

The secondary lock is a feature on the connector body that retains the pins. This must be lifted before the new contact is pushed into place. It is hidden behind the black plastic hinge lever on this connector, gently remove this to expose the secondary lock tabs (two white rectangular plastic bits), lift these up slightly to unlock the contact pins and allow the new one to be inserted. When the new pin has been inserted, push the wire secondary lock tabs down and reinstall the black hinged piece. The instructions failed to mention that the secondary lock tabs are hidden by the hinged bit.

My installation works using the existing unused wire referenced in the instructions.

I have some pictures that I will add later.

If you use the Canadian Harness you don't have to run anything from the battery or cut or pierce any wire insulation or wires. I don't know why the Canadian stuff is so much better than what is sold into the US market.