Only way to control the brakes is to add a 12 volt system to your truck and run a pair of wires for the trailer's power. Now, nice thing is that the 5 tons have a 24 volt power lead on the trailer harness so you can run that as a 24 volt power feed to run accessories on the trailer (like standard interior lighting or a 24 volt to 12 volt power converter to charge batteries).
My Deuce is setup to tow a trailer with electric brakes. I have a 24-12 volt converter on the firewall on the cab with powering a Tekonsha Prodigy electric brake controller. It's a true inertia type unit (not a pendulum type) so it's more reliable with the bouncy nature of the deuce. Bear in mind that you HAVE to run a 12 volt brake line and a ground return back to the brake controller for a low impedance ground, and you need 12 - 10 gauge for wiring to handle the high current even though it's intermittent. If you run a 12 volt lead to the trailer as well, you can then power a breakaway kit per DOT rules. Just setup a second trailer connector with a 12 volt Brake lead, 12 volt power and 12 volt brake ground and run the wires to the cab where you add your 12 volt adaptor. That also allows you to run 12 volt accessories in the cab like a GPS and other stuff.
