The system I use activates with the engine brake. It requires positive input from two sources to activate: 1) MH brake light on, and 2) toad is pressing inward on the towbar (ie moving faster than the MH). If either the MH brakes are released (ser...
It appears that most of the auxiliary braking system failures or malfunctions I have read about on here have involved the "brake-in-a-box" like Brake Buddy, etc. Of these, I don't know if any of them also used a remote indicator of toad brake activa...