wiring in 7pin plug and brake controller help

[usmc0311]

Alright I have a 05 ram 1500 without a tow package. I'm getting ready wire in a 7 pin plug and a brake controller. Questions I have is can I just tap into the hot wire on the reverse light in the tail light assembley or is there a certain place I need to do it at? Also I need to know which wire is the stop lamp switch wire is under my dash. The aux power from the plug to truck is pretty much a direct hook up to battery with a fuse correct?

 

[C.Carmichael]

Check under your dash.. There may be a light blue connector, factory trailer brakes.