Need Help With Wiring a Tow Package!

I have a 2006 Tacoma TRD Sport. It does NOT have the factory tow package. I want to install a 7 pin connector with a brake controller in order to tow a horse trailer equipped with electronic brakes. Has anyone done this? Is the white brake connector that is sometimes shown in photos under the steering wheel dash available with trucks that did not come with the tow package?
Any advice from someone who has tackled this would be appreciated.
Thank you!

 

I Just did this. the harness was behind the wires like all have said, but the only thing i used from it was the brake sense wire and ground. the other two large wires dont go all the way to where you need it.
So i ran a new 12ga wire from the battery (fused) to the cab/brake controller, then another 12ga wire from that to the back of the truck. I also added a second 12ga wire from the battery to the back of the truck for the aux wire in that 7pin connector.
I would also recommend putting in a large tranny cooler.

towed this last weekend, around 300 miles. no issues at all. 6000lbs lol.

 

https://www.tacomaworld.com/threads/the-tacoma-towing-bible.4031/