Actuator is on truck.... Breakaway battery and activation switch is on trailer.... Small tether to a pull pin comes out of switch and locks up trailer breaks... DOT and State law says in trailers over 1500 pounds it has have breakaway and to be able to hold trailer brakes lock for at least 20 minutes...
www.horsetraileraccessorystore.com
Excuse me but my electric brakes are powered directly from proportional controller under dash to magnets (actuator) on backing plates of trailer axles, the is no rudimentary receiver in electrical brake system... Yes there is some hydraulic serge system on trailers but they don't have any controls from operator cab..... Have not seem any pneumatic brakes on pick up level trucks (mainly reserved for LRGE trucks)...