Thanks for posting this question! I'm also trying to locate our brake controller wiring so we can install our controller unit as well. Was the blue wiring inside the white plug? It seems like I found a white plug with blue, green, red and white. I've attached a picture. Is this similiar to where you found yours?
Is there a reason why I would not just plug the wiring plug that came from the Thor in our manual kit? I've also attached a pic. I'm thinking I just plug that into wiring I found under dash then plug into a brake controller?
Sorry if these are newbie questions as we had brake controller installed previously in our truck when we towed a travel trailer but now've upgraded to the Thor ACE motorhome.
I'm thinking we can just move our brake controller (Tekonsha 90160 Primus IQ) to use. We plan to dingy tow a car and other time maybe utility trailer with dirtbikes.