Diagnose and test switches on the control panel,and even the arm limit switch.
Test battery trap voltages
Check for continuity through the cables and to check fuses
Measure voltages at the receiver socket, and at the receiver to pinpoint where the connection is failing
It's extremely difficult to rewire a plug on the trap if you are unable to identify the positive wire. Placing the wires in the wrong order could damage the trap or your control equipment.
PP3 battery included.
 We're unable to provide technical support over the phone unless you own a multimeter