Need trailer brake wiring help

I was starting a trip and noticed my trailer brakes, while there, didn’t seem “strong” enough. I turned up the sensitivity on my controller and it didn’t really help much. With a helper, I determined that only the rear axle brakes were buzzing when engaged. After closer inspection, the front axle wires were disconnected. It looked as though the wires corroded in the barrel connectors and literally fell out.

There are two wires coming out of the frame right above the axle, presumably from the brake controller. There are two wires going into the driver side drum and two going into the axle which I assumed are going across to the passenger side drum. I connected the two wires from the driver side drum to one of the wires coming out of the frame and the passenger side wires to the other wire from the frame.

No joy. Any suggestions on how to troubleshoot this?