Thanks for both answers. My problem is that I can apply the brakes with the manual handle, but I don't think I'm getting any braking from applying the truck brakes. I suspect one of two things:
The brake (light) switch voltage is not reaching the brake controller
The brake controller's pendulum is not indicating that I'm slowing down.
I believe that the connection from the controller to the seven pin connector is good, since I can manually brake, and I think that you've set me on a good troubleshooting path.
Thanks