For my RV, I installed a manual battery switch on the trailer's tongue area. And, I installed it properly. re: Regardless if battery switch is ON or OFF, the trailer's emergency brake away switch will continue to have brakes. If one installs their own manual battery switch, ensure one installs it to only switch power to only RV's "main chassis" - instead of switching ALL 12V power. Thus, never worry if 12V battery switch is set within ON or OFF position (or vibrates to its OFF position while towing).