I don't know if this is the same set up, but he tows a boat or small SUV behind the trailer. Truck is an aging older Ford 350. Travel Supreme's are really heavy. He is way over the tow rating of that old F350. Any brake controller that is dependent of the TV slowing first is not going to work very well with his setup. He should look for an used MaxBrake controller. Or stay with a cheap time based unit, as he is asking the P3 to do things it can not with his setup. Chris
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/28080546/gotomsg/28088418.cfm#28088418