I have a new 2005 dakota . I treaded my 2001 in . I had electric trailer breaks on it and want to used same controller . but can't find the blue wire . When reading the manual, I noticed that it says (that plug into the blue plug under the steering wheel above the brake pedal).

 

your truck shoud have come with the wiring connector that plugs into truck and then to brake controller as stated in owners manuel. mine was not there so i went back to dealer with owners manuel and made them give me one. dodge puts them in a pocket in the plastic seat covers to protect the seats during shipping.and most get tossed by minum wage cleaners. go to this ebay auction to see what it looks like (7983900403)