I believe the instructions say to program the board before hooking up any wiring, which is what you have discovered already. I built mine with a power switch to the box because I have it mounted in the car and didn't want it to have power when it wasn't needed. I also have discovered that when I power up the everything after starting up the car everything works until the GPS system starts up on the scanner, then I loose the remote head. When I power it (the Box) off and back on the RH readout comes back.