I just installed a breakaway switch on my popup, and everything is working fine. I wired it in to the full size storage battery on the trailer tongue and it seems to do the job. Now, I have been told and I have read in the instructions that if you disconnect the breakaway while the main trailer connector is attached to the tow vehicle, you will fry the controller. That would really hurt!!$$!! I would think that the trailer battery would feed 12 volts backwards into the controller to do the damage.
Heres the thought:
Any reason why one couldn't install a diode inline at the blue wire coming out of the controller to protect it from accidental feedback? Anybody try this? The idea makes sense to me and would give you that extra protection if someone accidentally trips or catches the breakaway cable and yanks it out.... hmmmmmm