Look for 5 wires in a white plastic connector for 6 wires hopefully near the obd connector...left side of steering column. Good luck finding the 4 wires that run to the back... finally found them behind the rear run box after giving up on finding them. Also the brake signal up front is not what you need...a ground is supplied...no +12V signal.
I wasted several hours trying to find the wires and finally mounted the brake controller in the engine area as everything you need is easy to find and once set I never change the gain (amount of braking) on the controller... one hour to install. If you find both ends of the wires I would use 2 of them for the output of the brake controller.
This post is my opinion (free advice). It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Sold 04 Dynasty to our son after 14 great years.
Upgraded with a 08 HR Navigator 45’...