Trailer light harness question - CX9

[psollitto]

I read all of the threads on trailer wiring harnesses. I found the 6 wire connector under the rear storage tray above the spare tire on the passenger side. I have checked out all the the wires in the connector with my test light and am able to identify what each wire does (left turn, right turn, brake, tail lights). I also see a ground and the last one which is power if the fuse is in place in the fuse block behind the glove box.

So here is my question. Why can't I just plug the wires of the female end of the standard 4 connector trailer harness directly to the vehicle harness?? Way back when, we would find the appropriate tailight wires and tap directly into them. There wasn't any black box between the vehicle and the trailer wires. The test light lights up when I connect directly to the vehicle harness plug; I can't see what it wouldn't work for the trailer lights.

 

[Yossarian]

For all I know, it may work fine. The circuit is fused at the glove box so you probably cannot do too much harm if it goes south.