For sniffing an existing connector I would like to suggest the use of wire wrap wire as shown in this video it worked well for me a while back when I sniffed a truck I have. See below attached pictures.
One pictures shows the wire wrapped on a pin. This made a good electrical connection, and the wire was small enough that it fit out the side of the connector.
A different picture shows the wires all hanging out the sides of the harness connector.
The third shows how I made a home made wire wrap tool. I drilled down the center of a small screw, then I drilled at an angle to make the small hole for the wire wrap. My tool didn't happen to fit this particular pin size, so I made one as shown in the picture. Here's a link to my wire wrap tool. http://www.digikey.com/product-detail/en/WSU-30/K104-ND/5985
I like it as you don't damage the wires.
Connector sniffing
Connector sniffing
Welcome to the friendlier side of internet crazy