Break-away Cable?

Remember, the whole purpose for the break-away cable is to pull the pin on the trailer tongue so the battery on the trailer will automatically apply the trailer brakes. As I understand it, this overrides the brake controller in the tow vehicle. Regardless if the chains hold in place or not, break, or even the trailer goes over a cliff, once that pin is pulled, the trailer brakes locked as much as they can be. It's designed to stop the trailer as fast as possible, regardless if it's still attached to safety chains or not. It really has nothing to do with the safety chains or anything else. It's about stopping the trailer in motion.

A few weeks ago I pulled the pin on my trailer frame (hitched to the truck). My brake controller in the truck was completely useless as my trailer brakes were locked down. And in order to free up the brakes, I had to insert the pin twice.