Electric Brakes Servicing and Testing for Tekonsha Prodigy.

The manual lever will work well up past 13 volts.

But the brake controller is enertia activated so no inertia present therfore no volts going to your trailer brakes.

At least thats my understanding of the unit.

Fred...if this any help....when I do my drums on the van etc, I use a 12 volt DC supply from a small battery via a lead with a switch that connect into the van 7 pin plug.

I adjust the shoes up so that the drum is tight and then back the shoe adjustment back off about 10 notches, some times a bit more, so that the drum brake shoes are only just touching.
Then I spin the wheel as hard as I can and flick the switch on...at this point the wheel will suddenly stop dead and as a result this has the effect of settling the brake shoes into position then with a another spin ( turn the swich off) I check they are clearing OK.

You may have to do this a few times until you get it right as the brakes only work if the wheel is turning as the magnet catches the spinning drum and this drags the shoes into the drum causing the braking action.

Hope this helps