An emergency breakaway system having an integral electrical testing system for confirming the functionality of a trailer's electric brake solenoids and electric lights includes housing enclosure having interface screen, a testing battery, and a testing controller. The trailer electrical system testing device is operative to replace a conventional emergency breakaway system, supplying the emergency breakaway functionality while also enabling real time, on demand testing of the trailer's electric brakes and lights. An integrated activation routine causes electricity to be supplied directly to the electric brakes in periodic, on/off intervals, thereby operating the electric brakes intermittently, for a predetermined time period. The activation routine thus allows a user to walk around the trailer and listen for activation of the electric brake solenoids as well as check and verify the functionality of the brake components.